What an amazing game, I higly recommend it.
Some feedback to the developers: I don't know if this was intended (I don't think so either), but I found that you can hit nearly every target and jump every obstacle just by spamming up and down at the same time (except for the ones that require you to hold down the key, ofc). I've beaten "Empy Diary" on hard just by doing that, but I have no idea how it plays on the other levels. A fix I would suggest is make it so if you press both keys when it isn't required it counts as a miss.
But anyways, I had a blast with it. The ost is a banger, the artsyle is beautiful and the mechanics are solid. I'm really looking forward for the full release.