Just made an account to tell you that this game looks and feels great.
I played it for roughly 2 hours by now, and in my last run I completely filled my note-sheet, and got circle blast to tier five (the yellow tier, if that was five). The build was ofcourse way too strong, at least before enemies started to deal double damage).
I'd like to see two things in the future:
1. The early game is really fun, since you can combine musical patterns in many ways, and it doesn't make much of a difference where and how you put things. If it sounds cool, go with it. However, endgame when the note sheet has been filled completely, the constant rythm gets boring. I'd love it if there will be certain rythm variations in the future, like changing the cadence. (If that is the right word). Currently, there are roughly 2 beats per second, 8 beats per cycle. If we keep the 8 beats per cycle, but "press" together 2 lines closer to each other, we would have a different cadence without affecting the actual dps. Chancing the cadence could either be an option, or a cost-free random item you can find (Like musical notes). I hope you get what I mean, else I'll have to draw a picture to visualize it.
2. Ofcourse things have to be added into the game, and this will surely come in the future. (This type of game has a good chance to become big). I just quickly wanted to remind you to add enough powerful non-flashy items. I've seen some bullet hells and similar games that went way too flashy, so that you cannot see anything anymore. Ofcourse, some people see the fun in chaos. Others don't, so it's important to keep a certain balance. The build I used in my last playthrough that I've mentioned already is a good example of what I mean. It was extremely flashy, and I could've gotten some real problems if I didn't cleared the room within seconds. It's still on the acceptable side though.
Anyway, I basically wanted to tell you my point of view. Hope this will turn into a topseller once it's on early access on Steam. You can already count in me and a friend buying it.