Biff needs to collect 10 crystals in a zombie apocalypse graveyard. Biff is armed with rockets (press "r"), bombs (press "b") and a laser (press "space") to fight the zombies. Don't let the zombies touch Biff, use your mouse to move him out of danger.
functions, simple messaging, simple events, advanced costume handling, simple sound playing, simple loops, basic math, visibility, graphic effects, delays,