The second video game iteration of The Real Ghostbusters, this game was exclusively for the Game Boy. It was released well after the series itself had run it's course, and quite possibly was a last-ditch tie-in.
In it, you play as Peter Venkman. It emphasizes puzzle-solving in a dungeon-like atmosphere. To advance to each new stage, you have to collect stars, which will open the door to the next level. The proton gun is effective only on blocks at the character's feet, not on the ghosts (bombs are used to destroy the ghosts). If you lose all your health (by touching damaging things like ghosts, flames, and reforming blocks), or the 999 second timer winds down to zero, you end-up losing a life. After successful completion of a level, you will be rewarded with a 4-digit password, which will enable you to start at the end of that level next time you play (the game had no save feature).