_Hidden Wonders of The Depths_ is a matching game with an undersea theme,
where three or more ocean fixtures have to be matched to clear a grid. The
objective is to clear the path leading to a treasure chest, so a crab can
reach and open it. Inside the chest sits a piece of a broken object that fits
one of the spaces of a jigsaw silhouette at the left of the screen.
The game has the standard variations to the formula, as well: chained tiles
that can only be removed after being matched, stone tiles that must be broken,
etc. There are sections with completely different gameplay, borrowed from
other casual genres.
In the hidden object screen, the objective is to click on a number of objects
and sea creatures within a time limit, without hints. Other gameplay
variations include concentration and jigsaw puzzles.