This brings back memories.
Ah, the Labyrinth Zone from the original Sonic the Hedgehog, a series of levels that introduced me to the concept of drowning in a video game. For me, the LZ was both fun and a nightmare. I can remember dying countless times for not getting to the air bubbles in time, not to mention there was a Badnik with a drill for a nose (whose name I forget) that would always give me hell when I tried my hardest to not lose all my rings. Orbinaut, the spherical Badnik with the rotating spikes, didn't bother me once you figured out its pattern (although it was still a bitch). I like how Sonic Team threw you a bone with the Dr. Robotnik/Dr. Eggman fight in the LZ by allowing you to finish the third act without having to beat him after chasing him through a narrow passageway chock full of obstacles.
Now that I've gotten my nostalgia out of the way, I'd like to say that this is pretty good. In my opinion, it's not as good as "The Lab (Bad Future)" was, but still a good job. I wish it could have longer. For the life of me, I know there's an old Whitney Houston song that sounds very similar to the original LZ BGM, but I don't know what it's called. Anyway, keep up the good work.