The open beta for Warframe started today. It's an interesting mission-based shoulder-shooter with some cool guns and customization options.
That said, their microtransaction system needs work. It wants you to pay for too much. But still, a lot of fun.
A lot of it's systems reminds me of what Bungie's planning for Destiny. Mission-based coop, drop-in drop-out features (Albeit a bit clunky in this game).
Give it a shot and hit me up if you feel like playing.
My tag is Euphorius.