A thinly veiled ad for an MMO. If the MMO it's advertising is as repetitive and boring as this game, I think playing it would be my newest definition of hell.
I think my favorite part is how it will not auto-switch your weapon to one with ammo. A close second is the lack of health, followed by the constantly respawning enemies, preventing a level from having any kind of tactical value.
I think Maxsimal has it right. The only way this game could be qualified as "good" is if it's trying to use every poor design choice of every FPS ever made. In which case it is spot on.
Like others have pointed out, the upgrades are almost completely worthless, as the other buildings get destroyed too quickly to matter - if you use their abilities at all, they are shield-less, and then they get destroyed. Would be much better if the building abilities were passive and you could choose which buildings got which upgrades. As it is, the only upgrades worth taking are the upgraded missile production and shield regeneration, both on the main building.
Kinda fun up to the invisible level. I both can't fire fast enough and run out of shells every time, then about 40 of the invisibles just destroy the base.
 "Omega Tower Defenese"){kind=icon}
 "Astral Tower Defence"){kind=icon}
 "Thing-Thing 4"){kind=icon}
 "MAD: Mutually Assured Destruction"){kind=icon}
 "Army of Destruction"){kind=icon}