For my 1. semester final exam I made a game called Pupper Pirates with four other people. The game is about a dog pirate and his battle against the cats.
The game had to reflect object-oriented thinking, and include everything we learned the 1. semester. We had to make the game using only Windows Form and GDI+. We had one month to make it.
GDI+ is not optimized for games. We decided to create our own framework to works as a middleman between GDI+ and our game. We invested a good amount of time in the framework which turned out to be a good decision. When it came time to write the game logic itself everything was a lot easier. We did not have to worry about the fact that we were using Windows Form or GDI+. If we needed something in our game we would just instantiate a new game object and our framework would take care of the rest.