Well, you made it. The world finally has a 2nd person shooter. It's an interesting concept you have executed very well.
I think this is the kind of core game mechanic that is instantly understandable but could take entire game to master. And this could easily scale into an entire game; getting more complex as the player slowly gets used to reorienting themselves every couple seconds. Players eventually taking the hindrance of having to move the camera into an advantage to see enemies behind cover, on roofs, and in neighboring rooms.
That end level maze was completely ridiculous. I was about to start drawing it out on paper before I lucked into finding the end.
I defiantly think you could take the SuperHot route and turn this idea into a full game. Best of luck whatever you decide to do!