Like other suggested just some simple tweaks to your ball for animation. Create a 2D animation sprite tied to movements of left and right and up and down. I did up an example in paint real fast to show how easy it would be to modify your main ball. You can do way better with the shading your current one has. I agree with the suggestions below so I'm not going to repeat them. For your first game good job! 

The physics is implemented well, and the moving ball adds some needed variety.

Could use a few things to add more fun:

- More variety. Most of the level is the same width so its mostly just the same motions. Needs more "enemies" and variations in the track.

- Player decisions? Like upgrades, different paths, etc.

- Some areas to get use to the physics. Early areas should be more tutorials, like adding walls / wider paths.

- Checkpoint system. Far too punishing to fail toward the end.

Cool concept, though since the corridors are so narrow and there aren't any checkpoints it pretty much encouraged me to go slow. Going fast would have been more fun but too risky/would require too many restarts.

Very nice for your first jam! Felt smooth and calming, and the ice physics felt fair and responsive. Nice job!

Nice, I like that the game rewards patience, reminded me of the old wooden labyrinth puzzle games.

Some checkpoints could make things a bit easier and encourage risky moves, but I kind of liked the extra tension of playing through the whole thing perfectly. Definitely felt tension on that last obstacle haha.

Congrats on your first game jam entry!

Including some other options for changing your momentum could have made this game feel better (limited brakes, boost, etc), but otherwise good job!