Cool entry. I loved how the environment moved around me as I worked on the puzzle. I was able to escape through the place I entered from at the end, but once I realized it was (probably) unintentional I went back in. The cube that we're holding clipping through the walls was a bit distracting; you could fix that by putting that block on its own layer and making a second camera with the clear flags set to depth only, the culling mask set to only that layer, and the depth set to 1.