i would say i have to dislike it. 

Could allow for some even more interesting level design. A faster pace might make it more interesting,

I love the idea that shadow try to follow you! and also great artwork and music. it make me feel i'm in jp game! nice work!

i love platformers! the level is nicely designed to be a challenge but not too difficult. really like the time trial aspect. art and music are nice specifically the clouds and the opening screen music

I really liked the music, it makes you feel in that kind of japan and the art is well worked but not animated, the only downside is that you respected the theme of the colors.

the concept of "fighting your past" it's great, it incentivizes alternative routes and playstyles. Also the art is great althou it needs animations and better feedback when hitting the demon clones.
The setting is the strongest point, the mix of the music and scenery fits the game well