Tag: ROMhack

Legend of Zelda Overworld Randomizer

Another awesome Legend of Zelda romhack, this one by Garret Bright. This one is an overworld randomizer.

It takes the rom file for the original Legend of Zelda (not included), and replaces the original overworld map with a completely new map. The new maps are randomly generated by a seed function, and the seed value always generates the same map, so if you find one that you find especially interesting, you can easily share it with your friends, without copyright violations, by sharing the seed.

Hyrule #25325045

The randomized overworlds seem to be well designed, for a randomized generator, in that they feel like they are following similar design principles that are evident in the original game, meaning that the maps are playable, and feel like they are broken up into zones, much like the original. It doesn’t just take the existing overworld screens and re-arrange them, it creates new tile layouts for novel overworld screens that have never been seen before, and stitches them together to create a coherent overworld consisting of distinct zones.

But, curiously, some design rules that are present in the original game, are not followed in the randomizer. For instance, in the original, most dungeon entrances have a single enemy roaming around outside, but in the randomized maps, this does not seem to be the rule. Also, enemy placement seems to be less concerned about starting Link in a part of the world that is far away from the more powerful monsters. You can expect to start on a screen with the cave to the Wooden Sword, but you may find yourself surrounded by blue Leevers, Peahats, and Moblins sooner than you’d expect to run into them in the original. And the trick where leaving a single enemy on each overworld screen prevents the screen from re-spawning enemies again doesn’t seem to work any more.

I’ve always wanted to see more games made with the original LoZ engine, so this is probably one of the best things ever. Now I can play unique Legend of Zelda games for the rest of my natural lifespan. If only there was something that created new dungeon maps and new items as well. Perhaps we’ll get something like that one day. Until then, I’ll be burning every bush, and blowing up every rock, until I find every secret there is to find in a virtually limitless multiverse of alternative Hyrules.

If anyone needs me, I’ll be in world 25325045.

You can download the overworld randomizer at bitbucket.org.

Legend of Zelda HD Remaster

The original Legend of Zelda has received a HD remaster treatment by the romhack community.

The hack is playable through an emulator called Mesen. Mesen is free, and you’ll need a copy of a specific version of the original of the Legend of Zelda ROM as well as the HD remake files in order to play it.

Applying the HD remake files to the game is not difficult, but requires following a series of instructions that are demonstrated in the video below.

I gave it a try. The graphical updates give it a look on part with the SNES, and have a look reminiscent of Zelda III: A Link to the Past, although the sprites appear to be original artwork, not rips from the SNES ROM. Likewise, the audio sounds much like a SNES update of the original LOZ soundtrack.

The terrain sprites are fantastic, and make old Hyrule look spectacular. The repetitive tiled look of the original is completely made over, and now overworld features like bombable rocks and burnable bushes are a bit less of a pain than they were before — rather than having to try to burn every single bush on the screen, there’ll be one bush (or a small handful) of bushes that will stand out and look suspicious from the rest of the background terrain.)

I’m not as impressed by the character sprites. Moblins, Goriya, and Stalfos all look less charming than they did in the original. Creatures like Octorocks, Tektites, Leevers, and Kees look like they are done better, to me.

One thing I notice right away is that Link’s HD sprite looks visually smaller than the original, but his hitbox doesn’t seem to have changed. This makes him feel somewhat clumsy, and I kept colliding with enemies when it looked like I should have a bit of space between us. While I’m sure this can be gotten used to, to me it’s an unfortunate, huge, and immediate negative. Ultimately, enjoying a videogame comes down to gameplay, not graphics, and gameplay is impacted by an improper hitbox like this. I believe the developers of the HD Remaster could fix this pretty easily by making adjustments to Link’s sprite.

Another thing I noticed is that when climbing up/down stairs, there is no animation showing Link descending and disappearing into the dark hole, as there is in the original.

The HD Remaster enhances the game in a few other notable ways: increased bomb capacity, pressing Select toggles your B-inventory item so you no longer have to pause to the subscreen to select it, text draws faster, and the dialogs are somewhat altered from the original, offering better translations and more useful clues than were present in the original.

I’ve played through the first dungeon. I notice that in the dungeons, the map doesn’t seem to give you any visual indication to differentiate between rooms you have visited vs. rooms that you have not yet reached. This is another gameplay issue that I feel should be rectified by the maintainers of the mod.

Overall, this seems like a fantastic mod, very well done, but not without minor flaws. It is nevertheless enjoyable and should not be missed if you’re a fan of the original game. Nintendo legal often clamps down on fan projects like this, so if you want to play this yourself, it’s best to grab it while you can. Although, the maintainers do appear to have taken pains to separate the mod pack from anything that directly infringes on Nintendo copyright, such as the original ROM that is needed in order to make the mod pack work.

Superman (Atari 2600) alternate map Romhacks, part 3

After publishing part 2 of this series, I played my grid map romhack a few times, and I think it’s rather good. I don’t know that I would say that I prefer it over the original map, but this is certainly a viable alternative map.

After a few playthroughs, I notice a few things:

  1. The helicopter moves bridge pieces away from the Bridge screen much more frequently. In the original, once you’ve placed a piece at the Bridge screen, the helicopter would only rarely remove it.
  2. The helicopter seems to move pieces from their starting screen much sooner, as well.

I like both of these differences; they make the game more challenging, and I think, more fun. You really feel like you need to race the helicopter to complete the bridge task. But I think it’s worth experimenting with the map to see if there’s a way to restore the original design intent, by reducing the number of paths into the Bridge screen. It occurs to me that an easy way to do this is to make the two screens above and below the Bridge screen connect to each other, rather than to the Bridge screen. So the Bridge will exit vertically to those screens, but reversing course will skip over the Bridge, but still place you near the Bridge; players would need to figure out that they are “around the corner” from the Bridge in this map, which is potentially disorienting, but should be less of a problem than the original map, which puts you clear across into the middle of the other end of the city.

I do think that this map has a few peculiarities that make it sub-optimal.

  1. Some of the subway entrances are right next to their exits. There’s little point in a subway trip that results in you re-emerging on the overworld map one screen over from where you started. For example, the Red subway entrance is one screen away from two of its exits, due to being on the top left corner of the grid, and the wrapping effect. The Blue and Yellow subway entrances are about optimally located relative to their exit screens, and the Green subway entrance is directly above one of its exit screens.

It’s possible to remedy this by moving the subway entrances around, or by changing their exits to more useful screens for this map layout. I was reluctant to try this, because I wanted to keep the changes that I am making to the maps minimal, but it seems that these changes are necessary for the good of the game.

Metropolis 21/7

Another thing that strikes me is that I didn’t need to remove one screen from the overworld in order to have even rows. 21 = 3 x 7, so I could have made an overworld map of 3 rows of 7 screens. This might make the subways more useful, since it would make it easier to place the subway exits such that they are 3-4 screens from their entrances.

A 7×3 grid will allow all 21 overworld screens to be included in the new map. Again, I went to an image editor and re-arranged the screens to make a layout, then visually reviewed and analyzed the map for playabiltiy concerns, and made tweaks.

My first iteration of this was to lay the screens out in the original map’s horizontal sequence, and see how that would play. That map looks like this:

First iteration

Without actually playing it, it’s easy to miss things, but I can see that this map has a few potential issues:

  1. The bridge pieces starting screens are all on the west end of the map, and are nearby the Bridge screen.
  2. The Phonebooth, Bridge, and Jail are all on the bottom row, which makes the bottom row feel too important, and the top row feel unimportant.
  3. The “critical path” relationships in the original map are broken in this map. This may not be a problem per se, but it will make the new map feel less familiar to experienced players.
Superman bridge piece routes
The original Metropolis map has a very tight spatial relationship between the most important screens on the map. The new map layout breaks this by moving the Jail screen far away from the rest of the screens.

Otherwise, I think the map looks pretty decent. I’m not sure how I feel about the potential issues I mention above.

I do think that the Bridge should be the center piece of the map, so I shifted rows and columns in order to make it so, but the rooms are still in the original order, using the horizontal progression from the original map.

It’s interesting how shifting things around can change perspectives on things. With this view, I’m able to notice different things:

  1. Now all the “important” screens (Jail, Bridge, Phonebooth, Daily Planet, and all but one of the bridge pieces) are on the west end of town.
  2. But balancing that, all the subway entrances are on the East end of town.
  3. Subway exits are somewhat evenly distributed, but there’s a few interesting things to point out: The Red subway exits all line up in a column at the far west edge of the map, while the Yellow subway exits are all distributed across the top row. The Green subway exits follow a diagonal from the northwest corner of the map, moving southeast. And the Blue subway exits are scattered about as far from each other as they could be.
  4. Shifting the screens changes the loopback point at the top right, and as a result the screen that normally is to the left of the Phonebooth screen no longer is. Which, despite what I thought when I first decided to shift the screens to put the bridge in the center of the map, does fundamentally change the map. Then I realize… I did it wrong!

I can’t just grab the top row and move it to the bottom, and then slice the right couple of columns and move it to the left. That will not preserve the horizontal order of the screens. To do that, I need to grab the top-right screen, move it to the bottom left, and then let all the other screens shift right by one, snaking around. This approach gives this result:

Overall, it’s actually very similar to the first two iterations. It’s literally the same horizontal sequence as the first iteration, but it’s not all that different from the second iteration, either; the “important” screens are still mostly to the west, the subway entrances are still mostly to the east. I think the subway exits are a bit better distributed than in iteration 2.

The vertical path is quite different. I think this map will run slower, due to the placement of the Jail in the corner of the map, and its distance from most of the subway entrances, and the Phonebooth/Bridge screens. There might yet be some quick paths that will become apparent through repeated play, but for now I feel that the map feels disorienting because the Jail isn’t north of the Yellow subway entrance screen any longer, and I struggle to locate it as a result.

Certainly there are many other possible arrangements for the overworld map, and I haven’t even begun to re-design the subway. But I think this is enough to satisfy my curiosity, at least for the time being. I may come back and revisit this further if I feel a need to after playing the maps I already created more extensively.

There’s much more to do in a hack of Superman, as well. I would like to figure out how to randomize the starting places of the bridge pieces, for example. I would also be interested in figuring out how to put up a hard barrier around the outer edge of the map, rather than having the map wrap around at the edges. But these projects, if I ever attempt them, will have to wait until I have a deeper understanding of 6502 assembly.

Download all of my Superman map romhacks here:

Superman (Atari 2600) alternate map Romhacks, part 2

For the second alternative map, I needed to carefully re-organize the screens to put them into a grid.

There are 21 overworld screens, and so I will use a 5×4 grid, omitting one of the overworld screens, since there can be only 20 screens in a 5×4 grid.

Selecting the right screen to omit is important. The removed screen must not be:

  • A subway entrance
  • A subway exit
  • The phonebooth, bridge, or jail screen
  • A bridge piece start screen

One of my goals with this redesign is to keep the layout of the screens reasonably familiar to players of the original game. This is a formidable task, and technically impossible since I am changing the layout, but my goal is to make the changes minimal, and to preserve as much of the critical paths through the map as possible.

But just as important, I want the redesigned map to be balanced and fun to play.

To achieve this, I want the subway entrances and exits to be distributed about the map, and not clustered together too much.

There are 11 unique subway exits, and 5 subway entrances (counting the Daily Planet), so 16 of these screens have something to do with the subway system, and another three are the Jail, the Daily Planet, the Phonebooth, and the Bridge screen. (Both the Daily Planet and the Jail are also subway exit screens, so are already counted among the 16 overworld screens that are related to the subway system, but adding the Phonebooth and Bridge brings the total of “must keep” screens to 18, leaving just 3 redundant screens for possible removal.) I didn’t realize how tight the map design is until I noticed this.

After considering the matter for a bit, I decided that this screen would be the one to go:

But I just as well I could have picked this one:

Or this one:


I mean, they’re all kindof the same, aren’t they?

I note that the three “dispensable” screens all have a similar color scheme to them, green and white, and wonder if there’s something being communicated through a visual language here, or if it’s just a coincidence… there are two other green/light grey screens, the Yellow Subway entrance, and the screen above the Jail, which is one of the bridge piece starting rooms. So… probably just a coincidence, then.

At the edges of the overworld grid, the map will wrap around to the next row or column. As an experiment, I think I’ll also create a variation where the map will wrap around to the same row or column, but I think this variation will only be playable on Easy difficulty — because, when Superman is struck by kryptonite, he will be stuck in the current row of the overworld map, and if Lois Lane isn’t present on that row, he’ll be unable to get revived until she wanders in, or the helicopter brings her, which could take ages, and would be unfair.

I take a picture of the overworld, cut out each room, and put it into an image editor and move them around until I have them arranged in a 4×5 grid that I think will be satisfactory. I end up needing to move things around a good bit to achieve this, but I think I managed to do it while still preserving some of the critical relationships between certain rooms.

Here’s what I ended up with:

Grid map for the Superman romhack
I think this might be OK. And might make a cool quilting project, too!

Here’s the original map for comparison:

So you can see, there’s a bit of re-shuffling that I had to do in order to balance the map out, and many of the vertical and horizontal connections are different in the new map.

The major changes are:

  1. The one-way vertical boundaries for the Phone Booth and Bridge screens are two-way.
  2. One screen is removed from the overworld, to allow for an even grid.
  3. The Phonebooth and Bridge screens are in the center of the map. (Although, since the edges of the map still wrap, center/edge is all relative.)

The important non-changes are:

  1. The subway system exits are all to the same screens as before. (But, due to the shuffling of these screens relative to one another on the overworld, this does still mean there’s some significant differences. The key exits to get to the Daily Planet and Jail screens are the same as in the original, though. And several of the subway exits now get you close to the Bridge screen.)
  2. The bridge pieces are still found on the same screens as they were in the original. I didn’t try to re-locate them. (Sometime, I’d like to introduce randomization into their starting positions, and see how that plays.)

Now that I had the design determined, I had to hack the rom to make the changes for real. To do this, I went through the original code and noted the names of each screen, and figured out from the boundary change code the correct addresses for each room, and mapped them together. This was straightforward, if a bit tedious, but fortunately the map is small.

One thing I noticed as I coded the new map connections was that there’s a peculiarity at the top-right and bottom-left corners of the map, due to the way the rows and columns wrap; if you’re in the top-right screen, going up or right will both take you to the bottom-left screen; and if you’re in the bottom-left screen, going down or left will take you to the top-right screen. This doesn’t make sense, unless you understand the way the overworld wraps. If you get to the end of a row or column, continuing in that direction wraps you around to the next row or column, and at the very end of all the rows and columns, it wraps you around to the opposite corner, and so the top-right and bottom-left screens are connected to each other in two directions.

I have only played through this map once, and mostly just to test that everything was connected properly. I think it’s a viable, and interesting variation, but I wouldn’t call it better than the original. Certainly, due to the re-positioning of the screens, the quick path to the bridge pieces isn’t as short as in the original map, which means speed running potential for this map is reduced. Beyond that, the Phonebooth and Bridge screens are not low-traffic screens any more, meaning that you’ll often find gangsters on these screens, and the helicopter may find bridge pieces that you’ve left at the Bridge site more readily, which will again make it more challenging as the helicopter removes them again.

You can download the entire collection of romhacks here:

Superman (Atari 2600) alternate map Romhacks

So for the first alternative map, I will just make the Up screen the same as the Right screen, and the Down screen the same as the Left screen. This means that there will only be the Horizontal progression through the map, and that Up/Right will be “forward” and Down/Left will be “backward” through this progression.

You can download the modded rom below:

I playtested this, and found that it works exactly as intended. The map is far simpler to navigate, and getting lost is now virtually impossible. Fly up/right to go forward, down/left to go backward, and all overworld screens appear in order. The confusing one-way vertical borders on the Phonebooth and Bridge screens are eliminated.

The downside of this is that traversing the overworld map is slower, since there are no shortcuts to be gained by using cornering techniques. You still can rapidly advance two screens in the horizontal map sequence by going diagonal from near the corner, transitioning on both the vertical and horizontal edge transitions. But compared to the original, where a vertical transition would typically advance you between three and five screens in the horizontal sequence, it’s much slower, and offers no real opportunities for useful shortcuts.

The only real shortcuts possible are via the subway system, which I left unmodified. Despite playing this game over nearly four decades, I’ve never bothered to memorize the subway in its entirety — there’s little reason to. The only exits of real importance are the ones that go to the Jail and Daily Planet. But with this map, knowing the rest of the exits is potentially more valuable, because it can get you to the other side of the overworld in less time than any other method. It may be interesting to study the exits and try to figure out alternate layouts that might make the map more interesting by providing additional useful shortcuts.

I can reliably win Superman typically in 1:30, +/- 15 seconds, but this variant took me 3:04 to win on my first play. I’m sure faster times are possible. The gangsters seemed to be bunched up more, and rounding them up preoccupied me at first, leading to the helicopter moving bridge pieces away, which I think happened earlier than normal. But because the map is essentially a two-dimensional line, finding the helicopter was trivial, making any challenge increase by the bridge pieces moving around quite minimal.

My impression is that this alternative map might have made the game more playable for very young players, ages 3-5, and as an “easy” version for beginning players, much like Superman‘s sibling Adventure offered players Game 1 with a simplified map. But overall, the simpler map makes the game less interesting and less challenging to play. But if you’re interested in the game’s design, playing this variant to see why it’s less interesting is… well, an interesting exercise. I invite you to download it and play it for yourself and make up your own mind. If you do, please drop a comment and let me know what you think.

My next Superman romhack will present the overworld map as a grid.