Some Free, Open Source Puzzle Games

Flipout

Can you imagine what a mix between a Pin-Ball machine, a physics simulator and a breakout clone would look like? Well your wildest dreams have been answered! Check this out:

Flipout

The game Flipout combines all this, and is a very challenging game in addition (didn't manage to even complete the first level :( ). But try it yourself ;)

Mechanical Tower

Another pretty interesting game by the same author is Mechanical Tower, a self described tower defense game: "but instead of defending with towers, you defend in a tower, with traps"

Mechanical Tower

Again the skill level required is quite high... but maybe I am just very bad in puzzle games :p

Jumpman

Another already a bit older puzzle game (Jumpman) has come to my attention since the neat (but closed source) indi hit And Yet It Moves seems to be based on it:

Jumpman trailer

Interested? Well it is pretty hard also :( But don't get discouraged and download it here. Licensing is a bit unclear though... seems to be MIT like, but don't quote me on that ;)