Loved it
Great game. And it should go without saying, if you can't read Japanese, don't buy the Japanese version! Of course it is going to be difficult to understand.
That said, the card system is really good, I'm pretty impressed with the new style of gameplay. It's not like MG on a PS2, but then why should it be?
There are a few awkward things in the game, watching huge dialogue cutscenes over and over again if you die, opening doors, at times frustrating camera angles, but nothing so severe as to outright ruin gameplay.
Recommended to anyone who isn't expecting a brainless shooting game.

A real good game
Metal Gear Acid is a game, that you must have. I think, that Metal Gear Acid is a new strategy und action combination. The Game is real good.

Takes Getting Used To...
This game has quite a steep learning curve, and at first it may be off-putting.

But if you stick with it and learn how to use the different cards then this game is very enjoyable.

Just don't get this game expecting a straight PS2 port (yet...)

Very good, but different
Great Metal Gear Comic Art Style, and collect the cards is fun. But I really miss the voices. I guess this isn't a game for everyone, and I also would have liked a "real" Metal Gear more, but nevertheless this is a good game.

An odd idea, but very deep gameplay.
The game is excellent... once you get the hang of it. A helpful tutorial is essentially nonexistent, but when you get the ins and outs of the deep gameplay, it's a rewarding experience. One of the big pluses of the gameplay is that while it isn't a stealth-action game and is really a strategy game, it's much nicer as a portable game.

As long as you find a guide of some sort to help you get a feel for playing it instead of wading through rather frustrating dialogue trying to figure things out, I highly recommend it for fans of the MGS games and strategy junkies alike.