In this Tower Defense game, you don't build or upgrade towers, they're already in place. However, they're only active when they're powered! You have to make sure that they don't run out of battery power, and keep your broadcast dish safe!
WASD to Move, E to pick up/drop batteries, Space to jump (and skip tutorial notifications).
Gamepad (PS3 Controllers confirmed to work)
Left analog to move, South button to jump, East button to grab/throw.