Defense Grid 2

It's good modern tower defense game. Works fine and voice acting is a plus. You can save any time. There's multiple "challenge" options for every map. It's a bit too easy on normal, a lot easier than the original, and after completing the story mode there's not much to do. I would appreciate an official expansion with more challenging levels.

I only need 4 co op achievements to unlock them all. This is still the best Tower defence game around. Help me. I'm 46. This is on my bucket list. Time is short lol.

Smooth, quick load, good maps and challenging levels. Worth the money and is definitely re-playable.

As a fan of the original Defense Grid: The Awakening (and all DLCs), I was excited to dive into the sequel and see what improvements and changes had been made. While Defense Grid 2 is a solid game that offers some exciting new features and levels, it's not without its flaws. I feel there is less challenge.
For instance after 15 hours into the game... I did already unlock more than 80% of the achievements...
For comparison, in the first edition the Awakening with all DLCs it took me 170 hours to unlock All achievements (around ~130/140 hours to reach 80%), you can understand my surprise.... And by seeing what are the remaining achievements to unlock in DG2, I already consider that it is done :(
if in the first Defense grid: The Awakening, grinder was somewhat challenging, in DG2, I got gold on gold on gold, I stop to build around the 30/40 wave, thus the last 60 waves out of 100 I'm just watching the carnage without any need to build more towers... Is it too easy or is it me becoming too good with the first Defense Grid The Awakening...?
The game's core mechanics are still enjoyable, with the goal of protecting your cores' base from hordes of invading aliens using an array of towers and upgrades...
Bad news, there is no more Flyers, thus the missiles tower is just for ground targets.
The new tower types, such as the "Boost" tower and the "Shuttle" landing in the beginning, are a welcome addition and offer some fresh strategies for players to employ. However, the game's pacing can feel a bit overly easy.
On the other hand, the game's replay value is still very strong, with multiple difficulty levels and special challenges to keep players engaged.
In the end, Yes I'm hooked with this second iteration of DG, but DGA (the first) still hold the gold medal in my opinion.

A very detailed tower defense game. I provides 20 levels and various levels of difficulty. It does have a multiplayer version and a map making option which I have yet to try out but definitely a top notch tower defense game for the masses.

Pros: interface seems to be designed for a controller (keyboard & mouse supported), subtitles available, keys are customizable, vsync can be disabled, “how to play” & “video tutorials” available on the main menu, “prologue” tutorial mission available, narration & presentation, voice acting, campaign mode & multiplayer, customizable difficulty settings (from easy to elite), basic graphical art style but very stable performance (100+fps), “F” to speed up time, hold “L” for awesome orbital abilities, soundtrack fits the theme

Cons: basic graphical settings, the aliens look uninspired & generic, there is no audio cue for when the orbital cooldown is ready, storyline is lackluster & ending is anti-climatic

Overall, a premiere tower defense game with cheesy voice acting, the story campaign is approximately 8 hours long.
Defense Grid 2 has my recommendation.

A fun tower defence game. I mostly ignored the story (sorry) but the levels are interesting enough to keep you engaged.
I still play DG2 for a level or two from time to time.
My personal awards:
MVP: Temporal
Best overall: Concussion
Value-for-money: Gun
Range: Meteor
Get it on sale and kill some aliens!! :)