I remember playing the Warframe beta years ago thinking it was pretty and the combat system was cool. What a shame that it was confusing, the UI was a mess and there was little point to it.
But coming back to it now, it doesn't look like the same game from years ago. I'm shocked. I had no idea it had space combat. The Second Dream update they made introduced some really good actual story. what. in the hell. It's also played by a lot of people on Steam.
I cant think of many games that improved and expanded that much. It's really quite incredible. The game is fast, tight and feels like a co-op version of Metal Gear Rising.