Underwater The Game is published by GameEra Inc but apparently developed by a Russian team. Mikhail Solovyev is the named seller in the app store but there aren't any credits in the app itself and the only website linked from iTunes is game-era.com which doesn't (as of this review) have a listing for it at all.
The gameplay combines elements of Tetris and Bejeweled with an underwater motif. 'Blocks' of colored jellyfish (3 per) float down the screen at a set pace and it's your task to line up 3 or more of the same color jellies vertically, horizontally or diagonally, at which point they pleasantly pop off the screen, everything shifts down to fill the space and you rack up some points. Your interaction with the blocks consists of moving them left to right and changing the color order. Quite familiar stuff to be certain so let's see what else it offers.