Puzzle

Vovsoft Picture Puzzle is a simple game where you have to swap pieces around to get them in the right spot.

A nonlinear 2D puzzle platformer taking place in impossible spaces.

Terminal-based puzzle game collection

All environment types from TrackMania 1, Sunrise, and Nations Forever, united in one game.

Pingus is a free Lemmingstm-like puzzle game covered under the GNU GPL. It features currently 77 playable levels and runs under a wide variety of operating systems (Linux, Windows, MacOSX, etc.)