Open Sonic is a free open-source game based on the "Sonic the Hedgehog"
universe. It introduces a different style of gameplay called cooperative
play, in which it's possible to control 3 characters simultaneously.
Unlike most similar games, Open Sonic provides a greater level of
interaction between the player and the levels. It's more than just a
jump'n'run; the user must come up with some strategy in order to get
through the levels.