For those who didn't know: I'm just now getting back in to gaming after a very long hiatus, and I'm wondering why NOBODY here told me about this game. I heard White Glint and ConstructionZombie talking about it in TS, and it took me a while (of not asking) to figure out exactly which game they were talking about. I decided to download because, well, it was another game to play with clanmates. And, man, that's one of the most entertaining games I've played in a while. At lower levels it's kind of less-than-rewarding, but the gameplay makes up for that tenfold. It already sucked New Years night out of my life, as me, CZ, and Supplice looked up at the clock and realized it was 9 minutes past midnight. I can't get enough of this game.
Just wait until you start getting new Warframes and weapons - suddenly the game becomes immensely more fun when you start cleaning up screen worth of enemies at once, or drop the heavy enemies with only a few bullets. So great. Starting off is pretty 'meh' but after you get started it gets exciting pretty quick.