From Valve:
March 9th through March 16th is Tower Defense Fest on Steam, with discounts aplenty and games like these all week long.
The games you'll find on sale this week are all about building things; and then trying to prevent others from tearing them down. (If you've ever had a sibling, you can relate. Just us?)
Organize stationary units and destroy your enemies: Steam's Tower Defense Fest begins at March 9th at 10 a.m. Pacific on Steam.
