Yeah actually I should have definitely added a shader to show the player behind walls! You are right. So obvious now that you say it :-) I think Godot 4.6 even has built in capabilities for this so it wouldn't even have been any work :D
I wasn't sure about moving the camera. Now the level is directed towards the top of your screen because that gives you the most speed in that direction (with the power up teleport).
Good feedback thanks for playing!