Now that's great!
I can not really compare it to the "Super Mario Bros. Z" series, as it is so good in its own right! I was just impressed by how good the animation was and the constant stream of action! My only complaint is that it existed in an infinite loop which seems crass for something of such high quality. It seems like a sequel to something, but no number is in the title. The sprites used were very original and fun to just look at. My favorite scene is probably the fight with the awesome blue laser guns.