QMentat helps you practice mental arithmetic. It uses arbitrary-length fixed point arithmetic, and can handle any size numbers, only limited by the size of your screen (and in the case of division with an integer result, the speed at which the number can be factored). It is also quite configurable, allowing you to tailor the questions to your needs.
Quabro is an arcade game in which the goal is to destroy colored blocks with a ball using four paddles on each side of the screen to steer the ball and keep it on the field. It is inspired by Breakout and Arkanoid, as well as several of clones created later. It is written in Python using the Pygame library.
RPGRobotAlive is an aide to a role playing games. It displays a board with walls and representations of the players that you can move around the dungeon. You can also place treasure or monsters in the dungeon. The program only keeps track of the locations of things, so you have to apply the rules of the game yourself to determine what happens in an encounter between the players and the contents of the dungeon. This software is generic and can be helpful with many different kinds of role playing games.
RocketMan is a sci-fi fantasy shoot 'em up game. It features different algorithms for gameplay as in EnemyRocket.java. Everything can be jarred up into a mobile phone game. There is a sprite-based video codec included for use during gameplay. This way, you can make vessels talk to you on the intercom. Some levels are top-down and left-right vessel shooters (like R-Type), and some are left-right man-sized players (like Megaman).