Some clever puzzles here.
As many other players noted, there is a problem with the player constantly getting stuck. I can't tell if the problem is collision per se or whether it's friction. If the latter, just create a Physics Material 2D that has 0 in the Friction field and attach it to the player's Rigidbody2D component.
Also, when working with pixel art, you shouldn't use interpolation. It just looks fuzzy.