Right now you can grab Warframe off steam. Its an awesome game. Basically think L4D or whatever where you can play single or with 3 other friends, thats how warframe is. Now the missions vary quite a bit, but at the same time feel similar. Upgrading your character and weapons is possible, and you can buy upgrades with real money since the game is F2P. Theres no pvp in it so its not the same as other f2p games where the best gear wins.
Like I mention in the comments of the clip, I didnt have physX enabled in it. I'm pretty annoyed it took a while for me to notice it too as I'm always straight into the graphic options the minute I play any game. But once I put it on there are a shitload of particle effects. The game looks gorgeous. I'll be uploading a video a little later which will show it. Anyway, great game. totally recommend it.