Really cool idea! My game is also a 2D grid-based puzzle game where you're unable to backtrack, but mine doesn't have the cool 3D stuff yours does.
It's really difficult at first to understand what's actually happening, so I think a slower-paced tutorial that gradually introduces mechanics would have been a great improvement.
Also, the decorations just create a lot of visual noise and make it harder to distinguish the rocks at a glance, so I think either increasing the contrast between passable and non-passable objects would have improved it as well, or simply removing the grass and other little details altogether.
Finally, I don't know how exactly you could solve this, but the inability to see the entire level at one time isn't ideal for puzzle games; all necessary information should generally be available to the player at once. Maybe some sort of indicator or minimap-esque ui element could assist in navigation.
Overall, it's a really neat concept with a lot of potential, but it's difficult to get into. Good job!