The landfill is very disorientating and feels hopeless... which I guess aptly illustrates the endeavour at hand.
So I found the chest first, after accidentally discovering the sonar while trying to jump, and was like OK now what, then came here and read the comments.
Then I found the level with the lights, which reminded me of the mobile game Glass.
Then the one with the disappearing platforms, which is incredible what you achieved with basically just the Unity cube! Part of me wants to experience that in VR, and another part of me wants to kill the other part.
Then I returned to the landfill and the game froze :(