Tonight I played A.R.E.S.: Extinction Agenda. A.R.E.S. is a Megaman-esque side-scrolling shooter with robots. This game is pretty fun, and I ended up playing well past my allotted hour. As you play you acquire powerups such as extra abilities and different weapons. Enemies drop resources that can be 'recycled' to upgrade weapons and create repair kits or grenade ammo.
A.R.E.S.: Extinction Agenda
Levels are replayable, with secrets that become accessible with later abilities, and each level is scored based on time, damage taken, etc. so there is replay value for those completionists out there.This game is a pretty good deal because it's fairly inexpensive for a good amount of fun.