Thoroughly difficult, which I will admit is the primary reason I'm deducting points. The trial-and-error nature of the game is a little harsh, though I suppose this is balanced out by the game's brevity (I don't see it taking more than 3 hours at worst).
Still, that such minute and little errors can cost a player victory seems unkind and unbalanced; many times I died simply because I wound up snagged on a corner for only a second or two. Also, in the final level, the necessary items are tucked away far too subtly. I walked past the map at least eight times before realizing it was there.
However, the art direction, the sound design, and the programming are top notch. For having done this in 48 hours, everyone involved outdid themselves.