Short bio: Computer Scientist, FOSS supporter (read more)
Tux Machines (TM)-specific
Awarding winning 2D physics based puzzle/sandbox game game Crayon Physics Deluxe is free for 24 hours.
In the game, you get to experience what it would be like if your drawings would be magically transformed into real physical objects. You have to solve puzzles with your artistic vision and creative use of physics.