Really great game. The graphics are good and funny, the sounds too. However the bosses are maybe a little to hard on the standard settings. At least for me :D I could not handle the randomness of Venus, Saturn and Neptune after their enrage. Until then it's quite easy to save hearts, but then it gets insane :D So, I really liked the possibility to go easy mode and see your games ending.
Love the story, but the intro is only written in the page. An intro in the game would have been nice.
The only thing which I have to criticize is the repetition in your moves. Jump, dash through boss, dodge attack, jump, dash through boss, ... So here is some improvement to maybe add different attack types, but for the game jam i think your game is really solid.
Nice job.
I would really appreciate it, if you play and rate my game too.