I participated in an event on DonationCoder.com called New Apps for the New Year (NANY) 2012. Lots of great freeware/donationware programs were created for NANY 2012.
I made something called Flipside, which is a game based on Sean Howard’s Game Mechanic #41: Flipside
This is a two-player game where both players play at the same keyboard (hotseat multiplayer). It has a very simple premise. You have a single board upon which you play using both sides of it simultaneously. Basically, one side tries to kill the other side. Players take turns moving units and attacking each other.
But wait, you say, if they are on two different sides of a plane, how do they fight each other? You’ll notice that each side has two different looking units in the corners. They are special units. They cannot be killed, but they also cannot attack either. If they are targeted and hit, they will be pushed back a square in the opposite direction of the attack.
But if they aren’t combat units, what do they do? They can flip specific squares from one side to the other. The unit with a + on his helmet flips all the squares in the same row and column (orthogonally), while the unit with an X on his helmet flips all the tiles going out diagonally from his position. The special units do not change sides at all, ever, but any other unit on a flipped square is moved to the other side regardless of which side he started on, unless of course one of the special units is occupying a tile that a regular unit would flip to.
For more information and to download the game, visit the Flipside game page.