I don't know...despite the bad reviews, this is still one of the most satisfying 2-D action games for the NES that I have played. Great graphics (very large detailed sprites), dramatic 8-bit soundtrack, primitive RPG elements (an experience system that's tied to your score), a long campaign that traverses the entire solar system, and tons upon tons of boss fights. The difficulty level is just right too...the first few levels are laughably simple and repetitive, but slowly things ramp up … more