I really liked the idea, but there are some issues that should be fixed.
1 - After dying, the character takes less than a second to start running again. This can become REALLY annoying if the player starts dying frequently in the stage before the lava world.
2 - The character feels too slippery. It takes a little while to gain speed, but once you do, it becomes too much and makes short platform sections frustrating. I’m not sure if the sliding movement is intentional, but ice levels have been hated since forever for a reason.
3 - In the last world, the final platform before the goal cannot be seen because the camera zoom is fixed, so it would be good to add some kind of visual hint showing where the player is supposed to go.