I now regret not having tossed my opinion of the original Defense Grid out there at some point, because my criticism of the sequel's going to seem like it applies to both titles. DG2 is what happens when developers get too high an opinion of themselves. I'm not referring here only to the relatively benign nuisance factor of an interposing interface but to the overall feel of the game.
First off, what's a Tower Defense game? When games like Dune 2, Command and Conquer and Warcraft established the Real-Time Strategy genre, their success was largely due to their more exciting, fast-paced gameplay compared to turn-based games. Unfortunately, that faster pace also tends to remove the "strategy" from the genre, especially when discussing kiddie-friendly Star/War-crafts. RTS games tend to devolve to mindless clickfests, cycling through units to give the same command a dozen times in ten seconds. Players even measure e-peens based on the most idiotic metric: "what's your APM?" (Actions Per Minute)
What do you do though if you like a fluid, real-time system but you don't feel like twitching onto your keyboard like some meth-addicted ADD brat? Some games have you only build unit spawners and place waypoints, but given the AI in most computer games is adept only in tripping and falling to its death, this can easily end up more frustrating than enjoyable. One solution is to limit the player to only one controllable unit (AoS games) - the other is Tower Defense. All the nailbiting pressure of normal RTS with 95% less spam by volume. Enemies charge in, you build turrets to destroy them before they reach their goal.
It's a simple concept, and that encompasses both the good and bad. Tower Defense has not quite yet acquired enough staple elements to qualify as a full-blown genre in its own right. In Warcraft 3, TD maps were a diversion from more stressful game types but never acquired the following of AoS maps. There was no equivalent of DotA or EotA for TD maps. TD is a sideshow.
The first campaign of Defense Grid acknowledged its sideshow nature. The aliens keep running through your maze without trying to destroy the things killing them. It's a ridiculous set-up. It's funny. When the basic concept is so comically incoherent, the last thing you want to do is try to pass it off as some convoluted Tragoedia in five acts. So to give the game some ambiance they hired one voice actor to elbow you in the ribs as he makes cheap puns and snide remarks while you go about the business of planting and upgrading towers. It was good, clean fun.
Zeke! Oh Zeke! Zeeeeeeke!
Unfortunately something terrible happened after that. Defense Grid got some good press. Microsoft endorsed it. Valve, which has every interest in cutting into Blizzard's derivative products from the Warcraft series, lent GLaDOS for a DLC pack. Word of mouth got around. Suddenly the development team started imagining they were making a major title instead of a Trine-esque play on a low-interest, derivative gimmick. DG2 takes itself very, very seriously. You find yourself listening to a radio drama involving a dozen disembodied voices and their little cliquish nettling which somehow affects the fate of the universe... yet it still has just as little to do with what you're actually performing on screen as DG1's rambling about raspberries. Across the board, DG2 wants to be seen as a much more "polished" product. The menus are glitzier, the expansive backgrounds are murder on slower video cards and the molten metal melts so much moltier. There is even multiplayer... of sorts.
Not quite so much thought seems to have been put into actual gameplay. Though a couple of necessary changes were made (for instance air and anti-air, which was never well integrated into the flow of the game, was removed) others simply made no sense (for instance the anti-air tower was kept and repurposed as a completely superfluous space-filler.) The multiplayer option is primitive and ignores the basic demand for higher program performance in competitive play. Instead of being more technologically streamlined, the multiplayer mode makes much higher demands on video cards, even in a simple 1v1.
As a continuation of the original, DG2 is neither here nor there. Yes, it's nice to have a buff option for towers, yes the new self-healing alien type is interesting, making minor alterations to terrain has high potential for custom maps, but all this is very nearly outweighed by the nuisance value of the self-conscious high school drama club voiceovers and the game's poor performance. Let's try to pretend nothing happened. Just wait for some DLC map packs to come out and imagine you didn't just pay good money for a side-grade.
What this thing is decidedly NOT is a true sequel. There were endless worthwhile ideas in the old War3 custom map roster which might have been included - if the devs' time and funding had not gone into staging a radio drama adaptation of Alien: Resurrection. Trust me, this game genre will never be one of the big players. You are a fringe element. A TD needs compelling characters like an adventure game needs hitboxes or a computer a pair of dice.
You don't need to legitimize yourselves by giving it backstory.
I'm not buying the game so I can sit through a sales pitch for the novelization.
Just give me more ways to laser and detonate baddies and slap on some cheap "shell-shocked" jokes. Boom!