Defense Grid 2 plays exactly like Defense grid 1. There are no major differences whatsoever. Now you can say "Okay, the game was totally fine the way it was so this is a good sign" however a sequel should in my opinion feature new stuff that makes it worthy to call it "sequel" and not "reshape". I know a lot of people think that DG is the King of all Tower Defense games, I disagree on this part, I know a LOT of TD games that I like more than DG 1 and 2. However I can admit that it is a great game on its own.
What made DG so great? The gameplay itself wasn't the case because, guess what, it was the most basic TD gameplay that you can found. You can found the exact gameplay in every other TD game. A small twist was the introduction of cores instead of a base health. this gave you a second chance to kill enemies that surpassed your defenses. But I'm pretty sure that everyone agrees that the major thing that differs DG from other TD games was the AMAZING voice acting of the AI. The narrator that explained how stuff worked, what goes currenlty on and adding stuff to the overall story was a good thing that made the game unique. I have to say that I have never seen another amazing voice acting like this in another TD game.
When you look at Dg 2 you will notice that the voce actor returns. This was of course the most logical decision of the developers. The Voice actor was the most rememberable part of the game, removing him would be the doom of the game. They added however some more voice actors to the game, maybe because they thought trippling the amount of voice actos would triple the amount of fun. It does not. I agree on 100% on you, Isaac, it's TOO MUCH. One narrator was fine, it was wonderful, it added to the atmosphere of the game. 3 narrators however are too much, you hear only how they bark on eachother, everyone commenting what's going on in it's own way and of course everyone knows it better.
In DG 1 you had a personal connection to the AI, just you two against the alien horde. In DG3 I have the feeling that I'm left out. You hear only the AIs chatter to ech other ignoring you all the way. Of course you cannot except that you will talk suddenly but it worked totally fine in DG1, why not in DG2? All this chattering and ignoring goes on the nerves. And that was in the first level already. Seriously, after the first level I STOPPED. I couldn't take it. After soem time I got back to the game but it goes still on. And even worse, when you finish the game you excpet that they stop talking. They don't, they go on when your victory screen shows up and the developers except that you sit there and listen to all the garbage they say until it's finished, not progressing to the next level. Of course you can skip it but that means that you loose bits of the story.
Overall I'm not disappointed of DG2. It's DG2 in a ne design, so that's okay. However I'm disappointed of the nerrator that had such a huge modification in comparision to DG1 that I just want to mute him. For fucks sake, there are aliens invading your base! Try to act like a professional!