Fits quite nicely into the metroidvania genre as a very early example, and a surprisingly good one for the time at that. The world is not too big at all, the full map fits on one screen and it can be completed pretty easily in about 3 hours. You can switch between four characters who each move differently and they all look goofy as hell and I love them. The starting one is named "Bop-Louie" for fuck's sake how can you not love Bop-Louie