If this sounds simple, that's because it is -- you'll be lining up lengthy chains within minutes. But you'll be surprised how much brainpower it takes to set up combos of multiple chains, and the many brainteaser-style puzzles include some real stumpers. Tidalis has co-op and competitive multiplayer modes (both online and offline); action-oriented modes and timer-less brainteasers; a lengthy, casual-friendly adventure mode; twenty unique game modes providing innumerable twists to the basic gameplay; dozens of special blocks and items; and over fifty minutes of beautiful music to go with the painterly art.
In short, several games' worth of content are built on top of this core mechanic, which you'll quickly find to be as iconic as it is novel.