In the Squirrel Eat Squirrel game, the game world was pretty simple: just an infinite green plain with grass images randomly scattered around it. The Star Pusher game introduced something new: having uniquely designed levels with tile graphics. In order to store these levels in a format that the computer can read, they are typed out into a text file and code in the program reads those files and creates the data structures for the level.
Really, rather than just make a simple game with a single map, the Star Pusher program is more of a system for loading custom maps based on the level file. Just by modifying the level file, we can change where walls, stars, and goals appear in the game world. The Star Pusher program can handle any configuration that the level file is set to (as long as it passes the
assert statements that ensure the map makes sense).
You won’t even have to know how to program Python to make your own levels. A text editor program that modifies the starPusherLevels.txt file is all that anyone needs to have their own level editor for the Star Pusher game.
For additional programming practice, you can download buggy versions of Star Pusher from http://invpy.com/buggy/starpusher and try to figure out how to fix the bugs.