
Warframe is basically Spiral Knights, only a) it's a third-person shooter and b) it's made by devs who are both competent and listen to players more than once per year. Kill dudes, get loot, use the loot to make gear to kill dudes harder with. However, unlike Spiral Knights, there's a lot of customization you can do with the mod system, and with the exception of the starter weapons (which are frankly trash and should be dumped as soon as possible) there's only two classes of weapons, with the "better" Prime class not being mandatory for progression. There's an anniversary promotion for a free gun until next Wednesday, so sign up now!
http://www.warframe.com/this space reserved for when I can actually fill this out