Feel like the connection to the theme here is tenuous at best. Having a finished game at all is impressive, for sure, but the ideas on display could use work.
That being said, for a platformer starring a black block, this is pretty fun. I like the different challenges for each room that require you to take different approached and play in different ways. The green room is downright evil though, it's got a bad habit of unceremoniously chucking you back out the door!
If there's one thing I definitely like, its the ability to jump even when in the air. It feels forgiving and fun to work with.