This is one of those games that can provide hours upon hours of entertainment. A cross between a first person shooter and tower defense with heavy emphasis on both.
Co-op play can leave quite a lot to be desired, but still works. Forget joining any host showing up in red for latency though, as you'll do nothing but skip everywhere across the screen and shooting mobs in the face won't even register hits (not even late laggy hits).
There are a few bugs, but nothing that was game breaking. A few others may disagree with that, but I had no issues with crashing etc. I am disappointed that the game sports DLC, since I'm really tired of forking out extra cash for a "complete" game. Did I buy the DLC? Apparently I did--bundled with the game--whenever I picked it up.
So is the game worth it? I think so.
-The gameplay is fluid and fun with responsive controls.
-The sound and music is good, though not "great."
-There are a decent amount of options to tinker with for better PC response.
-Story? Fail. There's not a great story in this game, and it's delivered in cartoony still frame comic book segments at the start of each mission.
So broken down into digits the summary score would look something like so:
Configurable Options: 7/10
If you're on the fence about purchasing this, I'd say give it a try. :) As for me personally, I enjoyed this game enough to go back and buy the first Sanctum, and even the 2D top-down game Super Sanctum TD.