Ghostbusters
Ghostbusters was released by Sega and developed by Compile for the Mega Drive/Genesis on June 29, 1990. It has nothing to do with the earlier Activision game (although their name still appears in the copyright screen), but is a run-and-gun game in which you control three of the four Ghostbusters from the movie as small comic figures, with Winston Zeddemore conspicuously absent. Initially, there are four levels available; after these are completed, a fifth level is unlocked, followed by a sixth and final level. Each level has a few (usually two) mid-bosses, known as "medium ghosts." When a mid-boss is defeated, it transforms into a small green ghost that you can capture for extra money by luring it into a ghost trap. Between levels, you can use the money to buy power-ups, such as a 3-way shot or healing items.
Story
The ghost hunters are stymied by a lack of ghost activity when suddenly several calls come in from all over town, including the reappearance of the Stay Puft Marshmallow Man (although the dialog indicates it's not the same one from the movie). After each case, a piece of a stone tablet is collected. The three ghost hunters put the mysterious tablet together, inadvertently opening a portal to the "evil world" and freeing a horde of ghosts. In the end, however, the ghost hunters manage to defeat Janna, the god of darkness, and retrieve a mystical gemstone from the evil world. They combine the gemstone with the tablet to close the portal and save the town.