Nice Monkey Ball-like. It's interesting how it plays more like Marble Madness in some ways. The presentation and basic controls are already pretty much perfect. My main issue for this build is the level design.
The levels are too long and repetitive. You don't need to introduce a challenge style and then every so slightly ramp up the difficulty over and over again. Just have the complete version straight away and I can retry until I get it. Slow escalation only works for games with infinite retries.
Other issues: The rolling sfx seems a bit off and inconsistent. Often it's not playing at all or is lower-pitched than what I expect. Conversely, standing completely still on a moving platform will play it.
I don't like how knocking enemies around is harder the more momentum you have. It should be the other way around. It feels like you apply the same knockback to them every time, but you yourself are knocked back more the more speed you have. It's boring to have to slow down to fight; that should not be the optimal playstyle. Or if they are to work this way, they should be sparser and the levels should be designed around the strategy of avoiding them entirely.
A drop shadow would be useful for making jumps.
Non-fullscreen doesn't work. Let me resize the game window, too.
All that being said, I had quite a bit of fun! I'll be looking forward to the next build.