PipeNightDreams is a game similar to the classic PipeDreams that runs under X11. It is implemented using the SDL libraries. It has 25 levels with increasing difficulty, and you can create your own by editing the text files. It has a lot of cool graphics, and a simple and fast interface.
vetetris is a game written in Java. It's similar to tetris, but it is played in 3D. There are figures which are falling that have to be placed in the right manner. You can rotate the blocks in six different directions and move them in five directions. As time goes on they move faster and faster, and it gets harder to put them in the right spot.