Puzzlr is a fast-paced multiplayer puzzle game based around teams working together to accomplish challenging puzzles and play through entertaining mini-games. It runs on a modified version of the Source Engine from 2007. As a result, this game has the minimal requirement of owning any Source game. Everything else will be provided by Puzzlr. This project is Open Source and can be followed on its Google Code page.
the texture for the cube isn't permanent. but it can now be used in puzzles and by the gravgun.
Hmm... it's way better than the normal cube from portal!
Thanks :D