SlackBuildsOrg/games/opensonic

Open Sonic is an 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.