The game is not insanely hard, it is manageable, I only hate you a bit because of the level in which there is a completely dark corridor and that slowly moving red block, it is constantly ruining my attempts to get the Touhou medal ;-) I also wonder what are some of the secret medals about, like Aint Portal or Wall Simulator. For others - I got some ideas that need checking.
There is also one thing that made me take a whole star from the game: the controls.
I'd like to ask why are you discriminating people that prefer arrow keys for movement? ;-) The same is about your - great ones - Strawberry games (waiting for more of them).
Back to controls issue: with the arrow keys I would probably earned more of the medals already, because my right hand+arrows=power ;-) But my right hand hates wasd and my left hand with that controls is not that good as my right hand with arrows. I also completely don't understand why many developers think that if somebody is a right-hander then should like the wasd more. I personally hate this scheme.
Concluding: make changes so the player could choose which control scheme wants to use :-)