Defense Grid: The Awakening is on sale for $5. Stop reading now and click the damn link if you enjoy tower defense. This game was, from what I could tell during the demo, not worth $20 or $15. But 5? That, my friends, is the price of a 5 dollar foot long at your local subway.
So instead of shoveling more cheap swine-flu-laced lettuce and the best horse snouts which can be placed on a cheap roll baked fresh from organisms (Subway’s Fred De Luca found in a neighboring galaxy but that was actually too expensive so he had to just use recycled sporks as filler instead) into your pie-hole, go down to your local Steam retailer and buy this tower defense game.