Mixes a lot of different game elements and absolutely NAILS the comic book feel!
Batman: Arkham Asylum is just pure fun. The gadgets and the combat really bring the feel of the comic book to your video game experience in a way that I don't think has ever been done before.
The combat reminds me a lot of Shenmue, where you often need to perform the correct attack to do damage, but it's in no way as clunky as Shenmue was. Battling big groups of enemies can be smooth and flowing, and when you launch the final strike, the game does a slow motion, bone crunching animation. The combat controls for simple striking are very simple, but you can also unleash some of your gadgets, such as the batarang, grappling gun, or explosive gel for extra excitement.
Arkham Asylum takes place on Arkham Island, which is not huge, but does include half a dozen very deep and detailed buildings which you can fully explore. The game makes use of the classic Metroid system of "explored through the story, pass a bunch of rooms you can't get to, get some gadgets, then come back and explore more," which works very well for the game. It works especially well in that you don't actually have to come back most of the time, but the Riddler collectibles in the game are addictive because it pisses Riddler off when you solve them!
Use of the gadgets is not immediate the most ergonomic experience you'll have, but you'll get used to it over time. Switching gadgets is done with the d-pad, and the game doesn't always select the one you want the first time you press it, but you're rarely in a tight situation where you need to switch gadgets on the fly. Once you have them out, they're simple to use.
Knowing the gadget to use often comes from using 'detective view.' When you employ detective view, a screen comes over Batman's eyes, and all textures on your screen turn a shade of blue, except for interactive object and enemies, which glow orange. Detective view is cool to have going into battle, because it also gives you x-ray vision, so you can see enemies from behind walls, and know which ones are armed. Unfortunately, the visuals of Arkham Asylum are often very attractive, much of the time with a Bioshock feel to them, and they inevitably get wasted on the fact that you'll probably spend more than half the game with detective view turned on.
Using detective view will be a massive benefit if you're going full stealth with this game, as it was intended to be (come on, it's Batman!). You will have the choice to add new skills and abilities as you earn experience in the game, with such choices as hanging enemies underneath gargoyles, increased armor capacity, and throwing up to 3 batarangs at 3 different targets at once. When you sneak around rooms unseen and pick off enemies one by one, you'll start to freak out their surviving colleagues (which you can see from their heart rate in detective view). The remaining guards will often even pair up, walking back to back, which will provide an even greater challenge to your skills. Combining your abilities with detective view properly can make Sam Fischer's (Splinter Cell) stealth abilities look like Big Bird's!
The debate as to whether Arkham Asylum can be considered a sandbox game is difficult to answer. You are able to visit much of the island early on, and retrace your steps a vast majority of the time (in addition to being able to explore the entire island after the ending credits), but the game is fairly linear. In fact, there was only one time in the whole game where I wasn't sure exactly what I needed to do because of the blips on the map. Still, you are given a good amount of freedom, and there are many ways to achieve some of the objectives in game. Personally, I'm an explorer: I spend time in games making sure I see everything, and get 100% of the items. Playing as I do, I believe I got a bit under 20 hours of play before finishing.
As far as additional modes go, there's challenge mode, which is more arcade style 'jump in and fight' than any story. This will provide about an hour of entertainment for most. There's no multiplayer beyond the leaderboards of challenge mode, but be realistic, would you really want a bunch of 'Batmen' in a deathmatch against eachother? (of course you would!)
Long story short: One of the best games of the year, great comic book feel, good play length, but most will not want a second play through. I'm going to call this a MUST PLAY and suggest renting or purchasing it.
All scores /10:
Graphics: 8.5
Control: 9
Environment scale: 8
Game length: 9
Replay value: 5
Fun factor: 10
Overall score: 9.5