Most frustrations I had were with the controls and the movement of the camera. The camera panning seemed a tad too fast and I believe it was the main cause of my deaths, which were mostly falling off pits. Landing on the edge of the ground also felt slippery, even when I wasn't in the ice area. Maybe that slipping wasn't intentional; it just felt awkward to me. The shoot key seems to freeze all movement for a brief moment, and I ended up taking hits because I wasn't able to turn around after shooting an enemy, particularly during the final battle. Also, is there a reason why there's no death animation for falling in pits?
Storywise, I definitely wanted to know more, like why Tess was having a bad day and what exactly happened. This was good, but the game alone felt like it was setting up for something bigger. Perhaps you would consider expanding it? Then again, sticking with a more abstract impression and leaving it up to the player's interpretation is not bad.
Tess' naivity was somehow comforting. I interpreted the aesthetics of the world to be how she viewed it in her own perspective. Tess' feet seem to blend in with the darkness of the background in the first part of the outside world, which bothered me a bit because it looked like they were disappearing half the time I jumped.
The gameplay mostly felt like Cave Story, but I love the touch of screen wrapping. The enemies were quite neat - my favourite was the one that stayed solid after death and how it had to be manipulated sometimes to get to higher places.
Soundtrack was wonderful and set the tone for the game. I felt like "Tess" loops too suddenly, but aside from that, I had no other issues with it.
Oh, your friend Milly was by earlier.
I'm sure this was intentional, but it didn't seem to read right for me. Maybe "stopped by" or "came by" would have sounded better. I dunno; it's just me. I never heard it said like that before.