Perfect blend of action and puzzle solving.
The combat is incredibly satisfying yet simple enough to jump right into. However, don't mistake simple with easy. Timing is important, and when you're fighting multiple enemies at the same time, button mashing won't get you through. The first time I put 10+ enemies into a dirt nap, combo'ed the entire chain, and didn't get hit once, I felt an immense sense of satisfaction. However, Eidos was very careful in illustrating batman's mortal side as well. You can easily see this the first time you get mowed down by gun fire from a small group of enemies. As the game progresses, you can see Batman's armor get torn, and cuts begin to form on Batman's body and face. It's this attention to detail that makes the game so special.
Environmental puzzles play a huge role in this game. It's deceptively simple, much like the combat, but will require a diligent eye in order to find them. During game play, I'm constantly surprised at the source and solutions to these puzzles. The Riddler's questions that asks you to take a screen shot of a particular item require extra diligence and thought. The eureka moments you get throughout this game is one that's fairly rare in video games these days.
The only knock I have against this game is the small glitches that happens often enough to warrant subtracting half a point. Throughout the game, the finishing moves may look like a kick to the stomach, but the enemy will hold his face as he falls down. You will also notice grapple lines disappearing and some clipping issues in fights.
Overall, this is a must play game even if you're not a comic fan. The details and thoughtfulness that went into this game is rare for a non Microsoft/Nintendo/Sony release.
I'm a proponent of try before you buy, and I also a believer in p2p file sharing. However, game developers or entertainers that develop outstanding titles such as this deserves to be rewarded for their passion and hard work. This isn't a quick cash-in but rather a work of love, please reward their great work by supporting them. Thanks.