Force: Leashed is a free and open source first person gravity fiddler puzzle game. To advance, you need to guide rockets to their targets using spherical potential fields.
Force: Leashed was originally done for the 7DFPS challenge. After that, a more polished version was entered in Assembly 2012 GameDev competition and the developers got the 2nd place.
The game is built with the DarkPlaces engine, which is based on the original Quake source code. Check out a video: