I put together a very short project that I conceived around New Years. Total project time was roughly 12-15 hours.
The game play is similar to a Rubik's Cube, but instead of having three dimensions you only use two. Since it is only 2d that means in place of getting all of the six sides, all rows or columns must match.
kongregate.com/games/InversionGames/color-slide
Please give it a try and rate