I always thought the card/turn-based gameplay wasn't worthy of the Metal Gear franchise, but after playing this I almost wish MGS4 had gameplay like this!
Or maybe not...
In any case, this game plays like you would expect a turn-based Metal Gear to do, and because everything is tactical and turn-based, the gameplay becomes a lot more detailed, allowing for a lot of strategies. You can take advantage of any situation, and are given all the time to plan.
The game also uses a card system for the 'moves', you can buy/sell and find them to assemble your deck, but still there is some luck involved as to which cards you'll draw in any one turn. However frustrating that sounds, it never becomes a real issue.
I'm still covering against walls and peaking out to shoot at drones... except this time its so much more! Throw a grenade at someone's feet, and use the second round to shoot it with your gun to detonate it... he might get knocked down/get set on fire/start bleeding/go unconscious, or maybe he'll just get lucky and dodge it altogether. The battles become very cool if you chain and plan your actions well, and it makes me wish this game had a 'replay' option at the end of each mission. Showing the entire round in one fluid movie.
The game isn't part of MG canon, so the story is even wackier then you would expect, and everything is greatly stylized with superb cel-shading. It really looks and feels like a comic book because of these factors, giving it its own identity in the MG franchise.
The game also comes with a pair of strange 3D glasses, which you can use to play the game in a special 3D mode.. this apparantly gives a depth of field effect, which you can then use to appreciate various movies of babes wielding guns, which are all unlockable when you get certain cards. I haven't tried this yet as I... don't want to open the plastic container that it comes in.
I highly recommend any PSP owner to give this one a try... but be warned that the learning curve is pretty high, and you won't know what you're doing the first hour of play.
Oh, and the breasts are awesome.