The controls were quite responsive, the level design solid (Though I do believe I'm now sick of spike-covered moving blocks). I liked how many detours you could take throughout the level for more flowers.
The atmosphere was very well crafted and very foreboding. The sound design in particular was wonderful, with the song playing near flowers being a highlight.
The art was good quality, though the cutesy player sprite clashed considerably with the tone of the rest of the game, as did the (main) ending. I did not have much interest in the story as given by the text, as it scrolled very slowly and was excessively cryptic.
I did not see anything particularly bad about this game. A nice and short experience.