The main issue with the game is that its base gameplay is difficult in a way that requires a LOT of precision, yet the controls aren't precise enough. Also, being locked at 30 FPS doesn't help. Losing a bossfight because the game can't keep up with itself and process inputs at the rate it demands of the player is extremely frustrating. Basically, the game never quite handles comfortably enough and it feels like I'm struggling with the controls, which should never happen in this type of game.
Also, the minimalist storytelling can be hit and miss, depending greatly on individual taste. While I liked it for the most part, I wouldn't mind a few more bits being a BIT more explicit. I accept that this is VERY subjective, however, and even then I'm mostly fine with it.
Beyond that, it really is a lovely game. The visuals, the style, the atmosphere, the music, the audio in general... all really unique and enjoyable. If the gameplay was just a tad better, it would be a masterpiece. As it stands, it's a somewhat flawed gem.