It is an interesting twist of match-3 mechanics with 4 different level types (collection, hunt, time challenge, exploration dive) and a free puzzle mode play, about a diver and his underwater adventures.
Use your mouse to match underwater pieces. Watch your oxygen level.
In Exploration Dive level you need to walk your diver to the end of the corridor.
In the Treasure Hunt, after getting the chest - you have to lift up the diver.