Cute artistic direction (although not sure if it's an homage or simply a lack of inspiration).
The game is awfully repetitive: every environment offers the exact same patterns and gameplay loops (find new weapon, forget about previous ones, two mini games, two races and you wrap that up with a boss fight).
The minigames are entertaining for a few minutes, but feel more like a gimmick to slow down your progress. Same for the races, some of them down right frustrating (the angles are weird and you end up hitting walls that didn't look that close).
So, apart from a couple of cute jokes, there's not much to motivate player to see the end of the game.
Unless you're desperately in need of an old school platformer, I'd recommend not spending money on this.