On the one hand: I found it really hard to control the ball. (Made worse by the fact that I kept forgetting which was left and which was right.) Spent a lot of time knocking it into the air and waiting for it to come down, or tossing it backwards instead of forwards.
This was made worse by the one point where I felt I was making progress, when I got the ball up near the top, and could flip it up to the next screen...but I couldn't get it to roll onto the platform up there, and it kept going down again. There's a jankiness (in my browser, at least?) that causes the game to freeze for half a second when moving from the red area up to the teal area, which made that sufficiently harder.
Eventually I knocked the ball back to the leftmost screen, and kept trying to push it up...until I somehow went off the left edge and now I'm stuck on an all-black screen (with the ball in the lower right where it entered).
On the other hand: this is such a unique mechanism for a metroidvania that I didn't want to give up. (Until, well, I had to, obviously.) I may well come back to it, and I'd love to see where you go with it!