Once I understood what was happening (kind of, anyway) that was a ton of fun! Really cool puzzle game, and the above/below mechanic was very well executed. In a way it reminded me of Forbidden Island with how tiles sink/are raised. At first I was thinking, "how on earth are people getting 600 points, what am I missing?" And that's right around the time I figured out how to 'save' tiles. Maybe. It was kind of addicting at the end.
The only issue I had was that it was a lot of learning to do all at once. I think once you have time to really flesh out a tutorial, that game has a ton of promise! Really great work!