Not a stealth, adventure, or action game. Third person Batmanner.
After countless unremarkable or even terrible Batman games, few had hope that the venerable character would ever become anything more than a blemish in video game history. But, with Batman: Arkham Asylum, Rocksteady, an up and coming developer that has only put out one other title, might have single handedly reversed that perception.
From the beginning, there is no doubt that this is a game which has been given the utmost thought and polish. Much like Half-Life games or Bioshock, there aren't lengthy cutscenes that may make you want to skip over vital information. After a brief clip of Batman transporting the Joker to the Asylum, the introduction becomes interactive. Throughout the game too, the story is mostly told through audio logs and in-game communication between Batman and the Joker, various guards, or Oracle, Batman's sidekick who provides him with useful intelligence. This in-game method of storytelling has moments of brilliance, using some interesting plot devices to keep things exciting. Voice acting is on the money, with a few voice actors from the Batman: The Animated Series reprising their classic roles. The Joker is definitely in his element, often referring to his diabolical plan as a "party" and making gags seem like life or death situations.
The music isn't overbearing, but it is appropriate and memorable when it is there. Several major Batman villains make appearances, and plenty of those that don't are given awesome allusions, often involving puzzles planted by the Riddler.
Technically, the game is quite impressive as well, with detailed character models and environments. Batman's cape flaps as he runs through Arkham Island, and his costume even accumulates tears and rips that remain as you progress further in the game. Notably, there is very little loading in the game, and when there is, it is cleverly masked as in the Metroid Prime games.
Where Arkham Asylum really shines though, is in its gameplay. This isn't only a stealth game, an action game, or an adventure game. It's all three genres fused into something even greater than the sum of its parts. As you stalk enemies and whittle them down, they'll grow increasingly terrified and eventually, they'll jump at any noise they hear. The Joker seems to find just as much pleasure in trying to kill Batman as he does in frightening his own crew, as you'll notice that he mocks them rather frequently.
Also, taking these enemies down is just as much fun as watching them squirm in fear. There's a variety of ways you can knock out your enemies, and in keeping with Batman tradition, like the rest of the game, these methods will never kill, but only temporarily incapacitate. Among the best is the inverted takedown, which lets you hang a thug upside down from a gargoyle. After, you could wait for more thugs to come underneath the gargoyle, and cut the victim down with a batarang, knocking out even more henchmen. These moments are priceless, and evoke a feeling that this is the quintessential Batman game.
When you aren't skulking around oblivious enemies, you'll be using gadgets to explore the massive island. Like in any Metroid game, some areas can only be accessed with an upgraded arsenal. Otherwise, you can search for Riddle Trophies, Riddle Challenges, destroy chattering Joker Teeth, or try to find Spirit of Arkham entries. Regardless of what you're doing though, you're likely to find the overall experience seamless and very addictive. The campaign can likely be finished in around 10 hours or so, but it is so entertaining while it lasts, that it's still worth the price. I have found that the "boss fights" are really the only snag in this excellent game. They really don't seem to fit the gameplay at all, and I found them more frustrating than anything. Yet, the rest of the game is so ahead of most others that it doesn't bother me much. I don't care much for the bonus challenge stages, but they are there too for added replay value, in case you found the main campaign too short.
Overall, this is a game that can't be missed. It is one of the most well told stories ever in video games, with enough mind blowing moments and engaging gameplay to even surpass games like Bioshock.