For the most part,
Metal Gear Solid: Snake Eater 3D is a traditional
MGS game. You sneak, crawl, reconnoiter, and use other subtle tactics to get from location to location, pausing frequently for cutscenes and radio conversations. Lethal force is often an option, though it's never the recommended one. Not that you won't get the chance to do some shooting, mind you.
Snake Eater 3D's control scheme works well, even without a Circle Pad Pro. Face buttons are an acceptable substitute for stick-based camera controls. The 3DS only has two trigger buttons, so item selection and similar tools are mapped to the touchscreen. This results in a decidedly more clunky experience, but there was no way around it.
I remember when Metal Gear Solid 3: Snake Eater came out. The survival-based mechanics were being touted left and right. To be sure, it's a neat concept that hasn't really been seen in other games, but the implementation doesn't go as far as you'd expect the franchise to take it. If you end up with broken bones and lacerations, all you really have to do is go to the Survival Viewer, sift through a menu screen or two, and find the proper item you need. Broke a bone? Use a splint. Cut yourself? Disinfect the wound, sew yourself up, and put a bandage on it. Food poisoning? There's medication for it. I had hoped that the 3DS's touchscreen might be put to interesting use with these applications, but Konami has settled for a straight translation. Oh well.
Hunting and gathering food isn't always necessary, but it's fun. As you progress through the game, you'll learn to use your gadgets to spot living creatures. It can feel gamey at times (no pun intended), but it's a fun diversion. It's equally amusing to put poor Snake through the wringer as he eats things that may or may not be poisonous and may or may not taste like pure ass. There's an odd sense of masochistic schadenfreude that comes with it.
If you've never played Metal Gear Solid 3 and appreciate video games as a medium for storytelling, Metal Gear Solid: Snake Eater 3D should be your next purchase. If you have fond memories of the original and would like to revisit it or take it on the go, by all means -- pick it up. It's hard to believe that this game is almost eight years old, but it's good to know that it's still a masterpiece.