This game is UNDER rated by GS...
The Graphics on MGA2 is amazingly good. The PSP power finally in good use. I mean, it's one of the best PSP graphics I've seen so far (aside from, Tekken DR) on the PSP. You'll be amazed on how well they did these graphics. The Cell Shaded characters are just so cool.
The cool part about this game is the 500+ Cards you can collect. All sort of variety and cards that shows character back to the original Metal Gear for the retro systems to the latest MGS3. The game has a card shop where you can buy or sell cards. You can buy like single or package cards, which much like what you'll do in real life. It also has a Deck Editor where you can edit your deck to suit you for each stage. It does take some time to learn the game, but once you learned how to play the game, you'll have a blast with this one, like I am now.
The sounds effects are great, you actually hear really clear and loud gunshot and movement effects. The Music is a nice touch too.
Overall, this game is a must have if you own a PSP. Don't buy the 1st Acid game, cause this one is WAAAAAY much better.