I'd love to tell you this is a nice Marble Madness/Monkey Ball-type-of-game - but sadly, it isn't anything like those games.
First problem is that the thing you control may look like a marble/ball but it doesn't act like one. You control the ball (not the world ala Monkey Ball) and the ball has minimal inertia (unlike Marble Madness) so if you release the controls, the ball just stops (that's not how balls work!?)
Second problem is the visual style. Whilst not unpleasant to look at, it completely fails to give you any sense of depth or position in the world. There's almost no way to judge jumps unless you're constantly panning the camera (you cast no shadow until you've almost landed) and objects cast minimal-if-any shadows which means there's no sense of depth/distance/perspective to work from either.
I didn't get that far in, but even early-on the levels veer away from 'game of skill and reactions' to 'memory test with stuff you don't see until it's too late' and that gets pretty frustrating.
All that said, it's perfectly playable as-is, but it feels unpolished and I think a lot of people will be disappointed...