Bubble Shooter 2 is a game mini-pack which includes Strategic, Arcade, Sniper, and Marathon games. The goal of these games is to pop all the colored bubbles that fill the board. It's a bit like Bust-a-Move or Bubblet, but with rather different and varying gameplay. It is highly addictive. There is an online contest for the best players. Versions for PalmOS 5 (hi-res) and for older devices are both available.
Burr Tools is a set of programs for solving some kinds of puzzles, namely puzzles that are made out of square, cube-shaped, spherical, or triangular units, and whose solution also contains only pieces aligned along those grids. The program finds assemblies for the puzzle and animates how you have to assemble for some of them.
CSudoku is a command line Sudoku solving program. It solves the popular 9x9 versions of Sudoku using Donald Knuth's Dancing Links algorithm. It was created as a fun exercise in computer programming and not necessarily to be a program useful to anyone in particular. There are many other Sudoku solving programs that are more refined and have many more features than this program would ever dream of having.
Card Monsters lets you play a creatures, instants, and sorceries. You to play the game against a computer-controlled opponent. Currently there are over 300 cards, and you can play in constructed, sealed, and draft mode. The program can automatically download all of the card pictures. The GUI is basic but very usable.