A prettier version of Slime Volleyball (Quin Pendragon and Daniel Wedge). See http://oneslime.net/.
An exercise in programming, game design, and getting my skills polished up.
Written in C# .NET 2.0 / Managed DirectX 9.
Have single player (player vs. computer), dual player (two people on same computer), and multiplayer (two people playing each other from different computers over a network).