Nice game. There is some-time where we are stuck, but levels are short, this was not disqualifying. I just wonder, why you choose those controls ? Why not let the free camera, and make your plug follow the forward/backward direction of the camera (and rotating if needed) with arrow up/down, and translate left/right of the camera with arrow left/right.
Knife is a good addition. Music is a but repetitive.
Graphics are nice, perhaps too much bloom.
Overall game was fun, and the idea minimalist and fit the them.
Good work.