You definitely got the Nier vibes down. I like the piano in concept, but it sounds a bit robotic, especially in the start. I think if you varied the note velocity and timings a bit it would be better. The best thing would probably be to record on a MIDI piano (or a real piano). Maybe it also needs some reverb to feel like it's in the same space as the bells.
As an alternative you could do the Nier Automata main menu theme thing, where they play one normal piano and a reversed piano at the same time to make it sound kinda creepy.
Very good composition overall, though!