Sporktris is a clone of Tetris-clones. It is meant to be fun, functional, and pretty, with as little annoyance as possible. It features pretty level backgrounds and colored pieces, customizable keys, high scores, and hopefully everything else you'd expect from a decent Tetris clone.
asq is a simple frontend for MAME/emulator cabinets. It runs in a terminal window using curses, and pops up an optional screenshot window. It uses MAME/emulator keybindings so you can control your MAME cabinet using just your MAME controls. (In fact, this is where the name comes from--player 2 buttons 1, 2, and 3 are "asq".) It can also remap your games to use MAME keys. asq is meant for people who don't want to use a keyboard and have lots of games to manage.
Snowball is a jump'n'run game in which the player controls Tux the penguin through the levels. The objective is to guide a snowball safely to the exit. To achieve this, the player can create ice blocks, collect keys, use transporters, etc. The game comes with a built-in level editor.
Vectoroids is based on the X-Window PDA game 'Agendaroids,' but uses libSDL for graphics, sound, and input, and includes nicer graphics, sound effects, and music. The objective is to survive wave after wave of giant rocks, which you must shoot to break into smaller pieces, until they are completely destroyed.
Kobo Deluxe is an enhanced version of Akira Higuchi's game XKobo. It adds sound, smoother animation, high resolution support, OpenGL acceleration (optional), an intuitive menu-driven user interface, joystick support, and other features. Kobo Deluxe uses SDL for graphics, sound, and input, which makes it possible to run the game on a very wide range of platforms.
Glypha III is a Mac OS X port of the classic arcade game in which you are placed inside an Egyptian temple and forced to do battle with Sphinxes in order to gain the honour of a place in the High Scores. The game is based on Joust and features sound and animated graphics from the original Mac version.