The game creates an unpleasant atmosphere. A combination of loneliness, anxiety ,and the feeling of being lost (It is was due to the music, game design, and lack of dialogs, that it was possible to generate this feeling).
The pixel art, although beautiful, is sometimes confusing.
There is so much the game doesn´t tell you that it makes it very easy to get lost. For the same reason buying upgrades feels like a roulette (you have an idea of what it does but you are not sure).
The gameplay never feels fluent, you constantly get stuck between animations and the transition between attacks is slow (you can get stun locked by some enemies).
The story was never clear.
I hated that the dash on keyboard was to the mouse´s direction instead of being controlled with "WASD".
At first, I liked how it promoted the exploration by not telling you where to go, but the lack of an explanation of some mechanics (invisible blocks), in combination with how hidden some points of interest where, and the lack of depth, made it so that in some areas, instead of exploring new zone, or fighting enemies I would have to spend a lot of time circling around the area looking for what I had missed.