Militia Defense is the first open source tower defense game that I enjoy and at the same time the first LÖVE-using game that I don't want to stop playing!
The game features four unit types which can be upgraded and sold. It creates complexity through different terrain (grass/roof) and long reload times. Militia Defense is mostly inspired by the non-free flash game Budapest Defenders.
Code and art were created by Tabasco and are covered by the MIT-license. I'm in the process of finding out the sound sources.
Impulse is a futuristic racing game in an early development stage. It looks and sounds nice although so far only some media is being loaded and super-basic movement is possible.
I hope the game will become playable soon. Impulse uses the Irrlicht Engine.