Great puzzle game!!! But I have a few suggestions:
1. Mamost gave make the movement easier, it was very difficult to control it.
2. Add a tutorial, I almost gave up on the second level, and was stumped at fourth level.
3. If you want to keep the movement as it is, then make the camera rotate with the player, like a third-person game.
4. A few solution to your collider problem is to make a custom character controller or switch to a rigidbody controller.