The VASSAL Engine is a set of general-purpose Java libraries for creating online versions of traditional board and card games. It provides support for game piece rendering and interaction, and supports play by email or over a live connection.
GSokoban is a puzzle game invented in Japan 1982 by Hiroyuki Imabayashi. The goal is to push a number of boxes to special spots in a maze, without getting stuck against walls or in corners.
Njam is fast-paced cross-platform pac-man-like game. In this arcade you move through the maze eating cookies and collecting powerups while trying to avoid ghosts who chase you.
Quack game is a polished tetris clone featuring nice graphics, music and sound. With so many tetris clones, why choose Quack? That's easy - a cute little duck watches you play and quacks whenever you clear a line.