Simple, charming, fun. What's more to ask for?
Unlike Bejeweled, Hexic involves more than matching pieces to maximize score. There is an end-goal, and the possibility of success or failure.
Except in the special "Survival" mode, simply matching pieces enough times does not result in successful completion, unless you're lucky by a factor of about twenty octodecillion to one. Instead, you must go out of your way to form hex-rings by rotating pieces around each other during the matching process. Only then is a special white piece created, which must itself be moved into a ring, thus creating the final piece that causes a "win" when matched with more of itself.
It sounds convoluted, but adds a much needed layer of complexity to what would otherwise be a stock Bejeweled clone. The special pieces allow you to rotate others in new ways, thus forcing a deeper level of pattern recognition when the number of colors, and subsequently difficulty in finding matches, increases.
The random dropping of "bomb" pieces, which cause total failure when not disarmed, makes Hexic surprisingly difficult for a color-matching puzzle game. It's a so-called "race against the clock" with every move bringing you closer to both triumph and oblivion. I personally am very skilled at this type of game, and yet I played Hexic for months before finally seeing the phrase "you win."
Hexic offers less-than-stunning, but effective graphics; a cute original soundtrack; and a replay value of about 3, with two alternate game modes and an Achievement for doing twice what it takes to win.
All things considered, Hexic is appropriately simple, well presented, and most importantly, fun.