So... how are the voices on this one? Did they hire better voice actors or does the girl with the nails screeching on a blackboard voice makes a comeback?

You know it.

I didn't even know that...
A) there was such a thing as a sequel to Aquanox (not that I played the first game or anything; always seemed painfully generic), or
B) that it was developed by Massive Entertainment, the respectable creators of Ground Control, or
C) that such needlessly tacky and tasteless cover art could be part of a 2003 game. Seriously, I'm getting really worried about the mental health of my fellow GOGers when I read several posts showering appreciation over utter garbage like this...

My guess is that GOG mistakenly selected Massive Entertainment instead of Massive Developments because of the similarity of their names when they added the game.
Massive Development developed the first Aquanox game, and I think GOG tagged that as a Massive Entertainment title at first too.

Ah, thanks for the clarification. Would have thought less of Massive E. if they actually had developed this game...

Awesome! This was a really pleasant surprise to wake up to this morning, though now it has me hoping more and more for Archimedean Dynasty as each week passes. Come on, let's get the whole trilogy up here! :D

As far as I know, no voices actors reprises their roles form the first game. As for the rest, check my post.

Voice acting aside, does anyone know if this is more of a SIM than the first one, or is the combat the same? From the description it sounds like you can switch between arcade and sim?

So you're rendering your opinion on what exactly?
Not talking to KEgstedt specifically, but before being sucked into the current GOGer Aquanox-bashing frenzy, check out the games' intros on YouTube:
http://www.youtube.com/watch?v=Dcvu4lXmCLw
http://www.youtube.com/watch?v=7Vlno0QDEDU
And if you need to complain about the cover art, here's the lead artist: http://www.conceptart.org/forums/showthread.php?t=166776

Edit barnstorming: The sixth picture GOG has for the game, gives a pretty good idea of the sort of writing./plot to expect here. Folks, this is no Iliad.
A few thoughts:
Voice acting - Frog will never again invade your lives. . .or ears. Lisa is also gone. The voiceacting is better (but I don't know about 'known') on almost all levels. The only problem. . .well.
Gameplay - About the same, with a few changes. More reliance on snipers/sniper weapons. The ability to change it between 'arcade' and 'sim' is there in the options, but I don't know what it entails. If it's anything like Descent 3s 'sim' mode, it'll just invert your mouse up and down. That's just a guess though.
Story - I could do with less angsty children in my games, thank you. The story itself isn't bad, but the primary character and his love interest are. . .well. . .kids. Frighteningly so. Nat is excellent and probably the best character in the game (even if he has more angst than everyone else combined). It ends up being interesting enough to drag you through to the end, which has a very nice cutscene that's a good length.
If you enjoyed the gameplay of the first, but not the story/voice acting/characters, give this a go.
If you weren't interested in the first, this doesn't present anything different.
Oh, and Aquanox 1 has multiplayer. Btw.

As for the game itself, while Metacritic should always be taken with a grain of salt I'd say an average rating of "59" and reviews being quoted saying Aquanox 2 is "a lobotomized first-person shooter" is a pretty good indication of the game's overall quality.
As for the cover art...oh, where should I start? The "let's sell some copies to sexually frustrated 12-year olds" see-through suit worn by that chick pretty much says it all. In fact, there's a pretty well-established natural law in particle physics which states that if you - for no apparent contextual reason whatsoever - decide to make barely concealed tits such a prominent part of your covert art you obviously lack all semblence of taste and should never be allowed to make art for another game (...which is just a slight overstatement of my antipathy towards that cover art and the specific brand of commercial cynicism which seems to underly it).
Oh, and the tits-per-pixel ratio on the web site you linked to seem very indicative of the artist's/artists' general inclinations (the web site's title is "Not Safe For Work - Nudity", which I find as hilarious as it is telling).

Anyone able to shed more light on this "sim mode"?
Also, just out of academic interest of course, does the cover girl actually feature in the game?

To reply to myself. A quick search on gamefaqs seems to imply that you can press "z" at any time to switch from FPS mode to Sim mode... so I'm guessing it's simply a different control setup?

listen to this man, he obviously knows what he's talking about, because if the "professional gaming journalists" find the game boring than it must be, its as simple as that (and metacritics aside, all three games in the series were actually well received in German press)
and yeah, quality of the artbox indeed is how a mature man can see if a game is worth his time or not, and obviously
you don't qualify as a mature man if you find breast attractive. Just a thought tough, I think that you are the sexually frustrated one, and not those 12yo, who
find a bit suggestive pictures attractive, I might even go as far and say that thats perfectly natural, but hey I'm obviously immature.
As for the game, if you liked the first one you'll like this one as well, because it just gives you more of what you loved and hated in the first one,
minus the multiplayer, but to balance the things they actually hired voice actors, who sound at least bearable, and thats more or less it. Unfortunately this is no Archimedean Dynasty but its a fun, fast paced game, and certainly is challenging enough, so no press button a to win here, you'll actually have to think about your equipmet before going in a fight, and then use it to your advantage. Story is rather decent as well, especially if you played the previous two games, only problem is the cliff hanger ending, that is even more frustrating if you take into account that we'll probably never see a conclusion to the series, even if JooWood miraculasy decided to make a third one, I think I heard that the writer died a few years ago.

Let's talk about tits-to-whatever ratio in paintings by, say, Rubens.