Tag: Space Invaders

InvadTris: A Ludum Dare 41 Game

Over the weekend, I participated in Ludum Dare 41. The theme for this Ludum Dare was “Combine 2 incompatible genres”.  The game I produced, InvadTris, is a mashup of Space Invaders and Tetris, combining the static shooter with a block puzzle game.  I’m very happy with it, and am continuing to develop it. It’s already a lot of fun to play.InvadTris

Play and Rate InvadTris

Post-mortem article


Notacon 9 Game Maker: Crash Course presentation materials for your consumption

Game Maker: Crash Course materials are online, open to the public on Google Docs.

Here’s what you get:

Presentation slides. Be sure to read the notes, there is actual information. More than would fit into the talk itself!

Space Invaders Kit. All you need is Game Maker installed and you can build it yourself! A great way to get started. Includes:

  • starter project file,
  • final project file,
  • final project .exe build,
  • sprite images,
  • sound files.
  • step-by-step instructions for how to do it!
  • project specification document — a good way to start out any project is to document what you want it to be. Follow this as a template for your own designs!

speed = s/invaders_count;

Another Space Invaders HTML5 update. The only thing I did with this build was fix the speed increase. It dawned on my after watching video of the original that the speed increase was gradual, not that it picked up at specific numbers of Invaders remaining. Reading about it on Wikipedia, I learned that the original Invaders were actually constrained in speed by the hardware, and that as you destroyed more of them, the CPU had fewer things to do so took care of updating the remaining ones in the phalanx faster and faster.

I still have yet to implement the bunkers; it’s not straightforward to do destructible sprites, and I haven’t yet looked into methods for accomplishing it yet, but apart from fixing the high score glitch that’s all that’s left.

Oh, I suppose I could give extra lives after a certain number of points scored, if you insist.

Play Space Invaders HTML5

Space Invaders HTML5 updated

I’ve uploaded an update for the Space Invaders HTML5 demo. This version is almost complete.

Play Space Invaders HTML5


  • Game Over works properly
  • Game resets properly when level clear

Both issues were caused because Game Maker HTML5 games do not work with user-defined Triggers when a game is built as an HTML5 application. I worked around this by re-implementing the Trigger code in the Step event instead.

New features:

  • Invader count is correct: 55 per screen.
  • Motherships.
  • Aliens speed up when their numbers are reduced. (This is proven in concept, I haven’t added all the speed ups yet. Aliens are still moving smoothly rather than marching in discrete steps.)
  • High Score screen now displays scores.

Still working on the High Score screen. It is not working correctly; the list only stores the top 1 score, not the top 10. It’s also not as pretty as it could be.

Game Maker HTML5 test drive & demo game!

Too tired to write full blog post. This shall suffice for now.

I finally got my hands on Game Maker HTML5 beta, and whipped up a quick HTML5 Space Invaders demo. It’s decent, but has a number of bugs that are not present in the Windows .exe build.

You can play it here:


What’s broken in HTML5: The game over function, and the level reset function. That’s basically it.

Still unimplemented: sound effects, high score board, the mothership, invader speedup.

I cheated a bit and made the invader movement be smooth instead of stutter-stepping. If I go through the trouble of improving this all the way, I’ll take care of that at some point.

Look for a post on my thoughts about Game Maker HTML5 sometime after Global Game Jam weekend.

In the meantime, play the Space Invaders demo and let me know how it works. I’m curious how it performs in different browsers, so definitely drop me a comment if you try it out, and let me know how it is on your browser.