A simple Space Invaders clone made in Intermediate Student Language, a variation of Racket used in University of British Columbia's CPSC 110 class.

How to run

Download invaders.rkt and run the file to play! You will need DrRacket installed with the Systematic Program Design plugin, which you can get by being in CPSC 110.

If you don't want the game to take around 15 seconds to download the sprites every time you start, download the respository (which includes the sprite folders) and change FROM-INTERNET to false.

TODO (probably not by me, but feel free to have a go at it)

• Make the movement less janky (keep track of which keys are pressed, not just when keys are pressed)
• Increasing difficulty every restart
• Score counter that persists across restarts
• Shields

Do you want to make a game in ISL?

It's a lot of fun, and very rewarding when everything starts working! It's also a great way to practice designing functions, data definitions, and programs for CPSC 110.

I would recommend doing a very good domain analysis before you start- there will always be things to change later, but editing your world state definition too much will cause some major headaches. And remember, always trust the natural recursion!

Acknowledgements

• lospec.com for the pixel art editing tools
• spriters-resource.com for the Space Invaders spritesheet