So the beginning parts suffer from empty hallway syndrome, where there's often nothing to do or look at other than run through many long boring hallways with some rings and enemies sprinkled through them. But then this level goes on longer and the laser gimmicks get introduced, and from there it all becomes quite entertaining! I like the boss quite a bit too, it's probably my favorite one of yours so far. It might help if the camera angle was a little changed so you could view the whole arena better, though. It's a bit disheartening to be surrounded in that red tint of death, only to have the safe zone be out of view.
In general, you seem to be at your best when you use Lua to make your own gimmicks rather than rely on SRB2's default tools! Keep doing more of that!