I'm too lazy to leave a big lengthy review. So I'll leave a small list-thing instead.
1 - Music is awesome. No complaints.
2 - Movement is fluid (I tried playing on my better, non-crappy computer and it was much better.) On my crappy PC it wasn't unplayable, just unbearably slow. I felt like I was cheating. The only reason I noticed something was off was because I saw what the actual gameplay was supposed to look like.
3 - Difficulty is okay. (In my opinion) it's not insanely hard, but maintains a relatively decent difficulty. It's definitely not "easy" by any means, but I wish there was an option to change the game like increasing the speed by a bit or making the the hitbox slightly bigger or something. The difficulty is definitely "high," but not as much that I'd break my keyboard. I can totally understand why some battles would be nerfed, but it's really good so far.
4 - The intro was a bit endearing. It wasn't actually that big of a barrage of information, because you only had to memorize a couple keys and just press randomly until you got them down. I may or may not have just clicked through it and regretted it for the first couple minutes of playing.