cave9 is a gravity cave-exploration game. It's a first person 3D version of the classic SF-Cave game. Your ship travels into a procedurally-generated cave at constant forward speed, and you have to control two diagonal thrusts to keep it from hitting the walls. As the game progress, the cave will twist more and become more tight.
papercut is command line based rock, paper, scissors game for Unix based operating systems like GNU/Linux, BSD, etc. A user can play the game by entering their choice of rock (R or r), paper (P or p), or scissors (S or s). papercut also stores user statistics, i.e. number of wins, losses, and draws.
Booruatsukaigaumai is a one-key desk game using OpenGL 3D scene rendering. Your task is to guide a number of red balls through 6 different levels full of blocks, holes, and gates. You have to make the balls go through as many gates as possible, which earns you the score points. However, you only have one key to control the desk tilt, which makes balls roll to the right (when the key is pressed) or to the left (when the key is released). Any other movement of the balls is controlled only by gravity and interaction with blocks, holes, and other balls. Even if the principle seems to be very simple, the game can be quite challenging.
Free Tennis is a tennis simulation developed by a former tennis player. Its main feature is realism. For gameplay, "realism" means you have total control over the shot parabola. For graphics, it means players have realistic gestures. For AI, it means real tactics. A two-player mode via LAN is available.
a2b is an abstract train game where you guide trains to their destination without letting them collide with each other. Each game is played on a set of tracks on which trains run at regular intervals. You pick a train and accelerate, brake, or stop as necessary to safely guide it to its destination. Since trains are continously being launched, more than 1 train will want to use the same section of a track, potentially leading to a collision. You must resolve this by making a train wait while you rush another train. As a last resort, you can send a train back to its base.