A single-player 4x4x4 noughts-and-crosses (tic-tac-toe) game, with a variable (and suitably tricky) AI. Deeply addictive, and perfect for when you should be doing something else.
A family tree viewer, displaying relations as a free-form network of nodes (i.e. people and marriages) and links (either marital or biological), automatically spacing itself by modeling relations as springs. The result is a clean and relatively intuitive view of potentially complex and convoluted data - incest and polygamy are no obstacle here - which has an organic quality making it great fun to just sit and play with.
A boids-like highly configurable 2D flocking simulation. Though each 'creature' behaves according only to three simple rules, seemingly complex system behaviour can arise. Through tweaking the specifics of these rules, behaviour akin to mammals, birds, insects, or even molecules in a crystal can be achieved.
A simulation of a series of blocks on a pivot sprung together in such a way as to allow waves to travel down them.
A version of the well known paper-based game Battleships for two Internet connected players. Features include no less than four exciting different weapons. Cor.
Play as either blue or red bacteria in an attempt to be more populous than the other by following the simple rules of your species' life-cycle.