Defense Grid 2 improves so much on the original, it's amazing.
I'll start off with the sole negative and that is the game sorely needs a "mute" button so you don't have to listen to the AI's. I'm OK with listening to them the 1st, 2nd or even 3rd time, but when I'm banging my head against the proverbial wall, I finally just gave up & put my headphones on my desk instead of listening to them while I'm trying Level 12 incursion for the 14th time.
Now that I have THAT out of the way, this game is just simply unbelievably awesome.
Some people will say "why on earth would I want to pay $24 for a TD game?"
This game has so much variety, it extends the gameplay 20x over a simple playthrough. While it does this through game variants like frozen core, or grinder and a handful of others, it has several different difficulties ranging from easy, normal, hard & elite. Then compound that with competitive, or competitive sell and I don't even want to do the math to say how many different ways you can play this game.
Then you have the entirely new tower upgrade system which will give you another 10-30 different powers PER TOWER to enhance tower abilities. These tower upgrades drop every time you complete a round and really change the landscape, literally. Where gun towers are uniformly weak on the first few levels, after you've completed the game, you're going to have some unreal deadly gun towers with abilities like ignore shields, or shield busters. Likewise with laser, target strongest enemy is a huge boost to not only survival but score as well.
Each of these tower upgrades come in levels, so the first level might not seem that big but when you've got an Inferno that lights everything on fire & anything they in turn touch will cause others to get lit with 20% damage, you know you've got something special.
This skill enhancement can make a level that was really tough the first time around, something really enjoyable the 2nd time around as you're able to contemplate entirely new strategies for how to employ an array of towers.
As you get the score boost ability, thinking of how to soften everything up so that they fall into your kill zone (where you want 2 or even 3 score boost towers as their sphere of influence is rather small) to maximize your score can change with every iteration as you get new gun upgrades or obtain new special AI abilities. Because score is tied to resources, if you can avoid using one of the special weapons to kill things, you can employ the resource generator to give you even more resources to maximize score.
Yes, you heard me, special weapons. Where before in DG1 you had the laser that you could employ, in DG2 you have about 8 special weapons (one for each AI in the campaign) so you can pick and choose and see which one fits your play-style.
The ability to use your WASD keys to move around & look at things from different angles is a nice touch. As is the toggle "F" to fast forward (in DG1, you had to hold that sucker down all the time).
I'm really looking forward to the creativity of people who create & sell levels using the free DG Architect. This will extend the game for a long time. Want some new variety? Visit the store! While I think the current pricing is a bit steep at $1.99 per level (I think $0.99 would be better), remember, you're not just buying one new level, you're buying about 20 with all the variants listed above.
This game is phenomenal. I'll be putting a lot more hours into this! Highly and I mean Highly recommended.