It's a great fun old school platform shooter:
And well worth your time if you like that kind of thing.
The absolute best part of it is that there's no limit on the number of times you can die - your score won't be as high, but at no point will the game pointlessly send you back to the beginning of the level because you failed to achieve something.
Having said that, the end of game bad buy is an utter bastard, and I died 123 times before I worked out how to kill him. Still, the game up to that point is addictively fun.