I do like the concept of the game as a ball roller with physics, but unless it's meant to be the Dark Souls of ball rollers, it could benefit from a number of changes to make the game easier.
Lives
To start with, setting the life counter to 3 or more when you restart or progress to the next level would serve to reduce tedium and mitigate the situations where one would willingly throw themselves off the edge and Game Over in order to reset the life count, so that they don't Game Over later in the middle of the level. If you were feeling cheeky, you could even do away with the life counter entirely, so you don't experience the frustration of restarting a level after clearing a difficult part. After all, the score resetting to zero is already punishment enough for a pro gamer. Maybe it should just be a difficulty option.
2-2 Ramp
There is a section in 2-2 where you require incredible momentum across a narrow path into a ramp to reach one of the red buttons. You must then also gain incredible momentum and leap off the moving platform back onto the ramp, where if you are shy of top speed, you will bump off the ramp and fall. Even if you do manage to clear the ramp, there isn't much time to decelerate before you're back on the incredibly narrow path. Maybe there can be a return path, maybe the narrow path can be widened a bit to make sticking the landing easier. You might even consider placing a checkpoint so you can get right back into trying to make the jump so long as you have lives to spare, because this one trick elevates the difficulty of the level from a medium to an extreme.
2-3 Boss
The boss fight on 2-3 took countless attempts to pull off. That's because bumping the blockers around the boss sends you flying off the small stage in most circumstances, and trying to fenagle your way around them is rather tedious. The shockwave attack in the second phase, as it is, feels blatantly unfair. If you're struck by it, you are stunned for <until you fall off the stage> seconds, and it strikes quite frequently, putting immense pressure on the player to avoid it while they're still trying to fenagle their way around the bumpers to actually hit the boss. That you'd have to hit the boss as much as you have to is just adding insult to injury at this point.
Boss Nerfs
If the boss fight is to be made easier than it currently is, you can start by halving the health pool of the boss. 8 attacks or so to bring her down to half health is a bit much considering how difficult it is to hit her, as well as how easy it is to be knocked off the edge. The shockwave attack is a very effective suppression tool, between it's stun duration and it's attack frequency. I would half these. Even a tiny disruption can end your life. Just ask any MOBA player. There are other ways to reduce the difficulty, such as halving the knockback of the bumpers, or shrinking them in size so it's easier to hit the boss herself, but at this point, the boss has already been nerfed into the ground. Maybe I'm being too hard on her.
Final Remarks
The game has real promise as a SEGA like, and you've emulated that era well. The first couple of levels were pretty fun, and I do appreciate the delicate art of effective enemy takedowns, luring them to the edge and giving them a tap. The only thing stopping me from enjoying this game more is the sheer difficulty of it. The game would benefit from a difficulty selector, with an easy mode where lives aren't a thing. I did rail on the difficulty quite a bit, but I did enjoy the game when it wasn't hard. The game has potential, and I'm looking forward to seeing where this project ends up going.
