A puzzle game developed independently by Matt Rix. Trainyard Express is the free version of the game Trainyard, in which players solve puzzles by creating a train track path connecting the train station to the train depot. In addition to seeing that trains reach their destination point, players must also meet additional criteria which makes each puzzle more difficult, such as: trains must be a certain color, join trains, or avoid obstacles.
The game has a really nice interface and you can upload your solutions to a community and see your solution animated via a flash player. It has connection support to Twitter and Facebook, a color blind mode, and multiplayer mode
Express has 60 puzzles available, plus some additional bonus puzzles.