This is great! I love the use of color for depth and oxygen level. The turning is tough in some of the tight grid sections. I got 2 of 4 tablets.
I think having 4 pedestals around the door, and having the tablets appear above the pedestals as you collet them would clearly convey the number of tablets you have left to find. I'd also like an option to "ping" those pedestals for a hint at where the remaining tablets are.