Metal Gear Solid Touch is a bad representation of Metal Gear Solid 4.
MGS Touch is set up in a way where you'll read a bit of text and then jump in to a mission. The missions consist of Old Snake hiding behind a piece of cover and then occasionally popping up to shoot enemies. You'll do this by dragging your finger to move where you're aiming and then tap the screen to shoot. Old Snake will always stay crouched behind cover, but only when you start shooting does he stand up and take the risk of being shot. If your health is dangerously low you can stay behind cover and your health will replenish.
If you've played MGS4 you'll immediately recognize the setting. Perhaps the worst thing about MGS Touch is that you don't move, at all. In each level you'll stay stationary, essentially an Old Snake turret if you will. Old Snake will stay behind his piece of cover while enemies pop out from objects within the level. The levels look like they took a picture in MGS 4 and made a level out of it for MGS Touch. If you zoom in on the level at all it immediately becomes a blurry mess. If not zoomed in it does look rather good for an iPhone/iTouch game.
Since it is a mobile game it does have its limitations. I encountered many cases where the game will slow down drastically when a smoke effect appears, an explosion occurs, or when something big jumps on screen. Luckily these effects don't last very long, but it's still enough to break the action.
Since this is a shooting gallery type game, playing it is mighty simple. Enemies that are exposed will have a slowly filling circle around them. Once that circle is filled and blinking red they will attack and hide back behind their piece of cover. Aside from just seeing cover with enemies popping out behind them there will be goodies scattered around, such as idols that can be shot for extra health or new weapons. Exploding barrels can also be shot to easily take care of surrounding enemies.
MGS Touch is like a story book broken up by fighting sequences. While MGS Touch does have the story of MGS4 backing it up, it's told in a way that doesn't make you care. The story is told through text which is summed up in a shoddy way. The overall quality is straight up missing in the story and doesn't play that big a roll in the game. MGS Touch tries to stand on its own, telling the story while giving as much background information as possible.
At first when I was reading through the bunches of pages explaining the controls, I was overwhelmed. The long tutorial made the controls sound complicated, pinching in for this, pinching out for that, scrolling, tapping, whatever. Getting into the game wasn't bad at all though. Your default weapon will be an M4 but if you pinch the screen you'll zoom in, which means you've switched to your SVD sniper rifle. To zoom out you pinch outwards. That's all there really is to it.
Since this is a Metal Gear Solid game, you'll hear familiar music and sounds. When you beat a mission you'll be rewarded with Drebin Points. With these points you can go into the shop and purchase various artwork. Other than that there really isn't a point to replay MGS Touch. If you have played MGS4 then there really isn't much point in playing MGS Touch, since the two vastly differ in quality. Ultimately, it's a sub-par shooting gallery game that isn't very Metal Gear Solid-like.
Perhaps the biggest flaw with the game is me. My hands are rather big so touch screen games have never been my forte. Using my finger to aim never works well for me since my finger will take up a huge chunk of the screen, causing me to guess where I'm aiming. Maybe I'm not the only one here?