Lots of people think that Unity is just for making 3D games, but Unity is also a really great tool for making 2D games. In this screencast, I walk you through the creation of a 2 player 2D game using Unity3D, the Orthello 2D Framework (a free Unity sprite animation plugin) and TexturePacker (for making sprite sheets).
You can download the project files that go along with this screencast on our website here: rocket5studios.com/tutorials/skillswap-making-a-2-player-2d-game-with-unity/