Not sure how the art came about, but if you did that art in 48 hours, you should consider make a full game with that style. Its incredible. The game is also fun. The skill levels make it feel like a metroidvania kind of game. Even tho i did find myself dying on purpose on the first saw just to upgrade fully, and then i didnt have time to win the level. So i think that its impossible to unlock all skills and win the game.