I'm playing the early access beta of Minimum, an online first person shooter by Human Head Studios and Atari.
The only game mode (for now) involves players killing creeps and then defending gigantic robots that assault the enemy base. Experience earned during each online match can be used to unlock new weapons and items to create custom loadouts. The pace of Minimum is fast; kill streaks make you weapon progressively more powerful until your next death. Resources gathered from fallen players can be used to craft balanced armor (and eventually, once enabled by the developers, other items) during a round.