Tombs of the Asciiroth is a puzzle/RPG/roguelike game you can either play in a Web browser or as an Adobe AIR application (available for Mac, Windows, and Linux). It is simple to play compared to most roguelikes, but the provided scenario should allow for some in depth game play. A map editor also exists to create new scenarios.
Deep Voyage is a collapse-style game in an underwater setting. The base mechanics are extended with many bonuses, anti-bonuses, and powerups. The game also includes a jigsaw mini-game and partially-interactive animated backgrounds which can be turned into screensaver mode when paused. During the game, the player helps a beautiful mermaid to win the royal garden design competition in Underwater Kingdom. So there is also a garden-building mini-game.
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.
Xye is a puzzle game in which the objective is to get all the gems in each level. The mission is not as easy as it sounds: there are traps, monsters, and very hard puzzles everywhere. The player can interact with objects in the game in a lot of ways, and some of the objects can also interact with other objects.