thanks for feedback. The idea is that player can use sounds to navigate (at least for the start) - there is a sound of hitting the wall (with 3d effect) and sound of scratching the wall (also enemies have 3d sounds). The strategy to get anywhere is to hit the corner and move in one direction until you hit other corner. However at the end, player has 3 items in total to reveal the environment, the final one is indeed ability that marks colliders with large radius around the mouse. So you don't have to bump into the walls in 2nd half of the game :)