I really like the idea of a character that can rotate and fall down in a platformer, and it's something I have thought of as a game idea after forgetting to lock rotation on some of my other platformer games. However, the only fun part of this game really is watching the character wiggle and rotate as you jump around. Platforming in and of itself is not fun (for more than a minute), and failure is especially demoralizing when you have to start all the way over.
That said, there seem to be a number of bug "features" in the game (you can stick to walls if you press into them and jump in mid air if you fall off a ledge. And you can essentially wall jump). They don't really hurt the game but I'm almost certain you didn't really intend for them. You can also get outside the level in level 2.
Lastly...the controls are bad. Enter, Arrow keys, and Space. and mouse. This game is simple enough to allow the player to play with a single hand and yet you require not only both hands, but also for the player to move their hand to and from the mouse (during level select).
Overall, the game mechanic simply needs more to interest or engage players in the game. The game in all areas falls pretty weak, in story, mechanics, controls, overall gameplay, even UI.