Cloudburst is a small minigame I created in a two week period of time. The goal was doublefold; I wanted to test out a new game engine, and also show that I can make games that have more than hardcore old-skool Genesis style graphics. ;)
Cloudburst is a scrolling 2D shooter with old and new style shmup gameplay. You fight in a simulated environment against computer-generated enemies. There is only one level of gameplay, but it features an unlockable second layer of difficulty. It has a unique scoring system where a "brush with death" literally nets you more score. And finally, there are both Mac and PC ports of the game.
The enemies are large and the explosions detailed, so you're going to need something with a decent 3D card. The slowest I've tested it on is a Mac mini (1.2GHz G4 with Radeon 9200 card.)
Controls are simple; Use the arrow keys to move, and space/alt/shift/control to fire. You can also use a gamepad, but note it only supports digital gamepad support. (ie: You can't use analog-stick style gamepads.)