The best of the series - no doubt
This game really kept that same feel, but added a lot of things that made even the hardest of situations _possible_, and really improved upon the original gameplay.
In this version of the game all of your squad has an inventory, and can carry loads of useful items around to be useful at your discretion. These items, specifically the ways they can be used, make the game much more possible to beat than the first. If there's actually any fault here, it's in the fact that there are SO many items, that you end up just sticking to a couple of trusty tactics that seem to work for just about every situation.
As I said before, the game is much easier than the first, though there are some very challenging moments in most levels. However, there can be ridiculously easy moments as well. On the third level, the one in the ice, I cleared the entire outside with just "Fins" with just a pack of cigarettes and a few well timed punches. Having the spy around just makes it ridiculously easy, as you can tell them to walk anywhere, and look in any direction. "Excuse, can you look the other way while my fellow spy operative knocks you unconscious and ties you up? -Ja, mein commandant."
The biggest flaw in this game is the sheer repetition. The first few missions are pretty cool, but after a while you seem to be beating a dead horse. I've gone through this game a couple of times, and the bonus levels, and it really starts to trudge in the last half of the game.
Overall, it's definitely worth a play if you like this genre of game.