I would have liked if instead of a little movement in each button press, you would have allowed the players to move freely. Even the default CharacterBody2D movement would be better. Also, not sure why everything looks blury but I would have like a bit more zoomed out camera. I kind of like the art though. But cannot interact with any button. Also, kindly allow WASD along with arrow keys for movement next time.
Nice job. I hope these critiques will enable you to make better puzzle games in future.