Atari's mech-on-mech shooter Minimum is having another free beta weekend, starting tomorrow morning and running through this Sunday. Returning players can simply login, and everyone else will have to head to the official site to claim their key.
Anyone can sign up, but if you happen to have grabbed a key last weekend and it doesn't work, you'll need to uninstall or sign up with a new name. Developer Human Head said in the announcement that those keys should work, but still gave the heads-up on what to do if it doesn't.
Minimum was originally announced from TimeGate, but more recently changed hands to Human Head. It has teams duking it out with the help of a giant mech called a Titan, not unlike a certain other game, but this one mixes in elements of MOBAs and Minecraft by letting you farm for resources to upgrade your brutes. You can see an overview of combat and crafting in the trailer from April.