Overall, I liked this game quite a bit. A charming atmosphere and a fairly intuitive level layout meant that I was done quickly and enjoyed myself along the way. The music helped make things nonthreatening, as did the soothing color palette. I admit I expected to be able to swim at one point, or collect another ability or something similar, but on the whole I liked the game's length and pace quite a bit.
The final level did manage to surprise me with its unusual background and nature. I expected more situations like that to appear, perhaps as foreshadowing, but it was apparently a one-shot thing. While novel,it *did* feel a little bit out of place - though a jump from the expected environment did help keep me attentive as the game neared its end.
I think I may have encountered a bug, however; I collected the keys found at both the top left and bottom right of the map before visiting the door, and found that only the top-left key had been placed, requiring me to redo the bottom right key puzzle. Perhaps this was necessary to ensure that the odd final level was the last one encountered, but I admit it was more than a touch frustrating to retrace my steps after enjoying myself so well.
So, a very enjoyable game, with lovely artistic direction and music, with simple enough gameplay to be easy but puzzles hard enough to keep me interested. Well done!