This game just came out of beta today. I have been playing it some and have really enjoyed it as a change of pace to the CoD/BF3 style shooters. It is free to play with micro transactions of course. It is developed bu Hi-Rex Studios over in Alpharetta. https://account.hirezstudios.com/tribesascend/?referral=784716&utm_campaign=email
My roomate is one of the lead designers on this game, i played OG tribes and Tribes 2, so far its a great game.
It means that if you want to buy Tribes gold or XP booster packs(you earn xp faster), you can do that with real money. You do not have to do these things. You can buy every item in the game with xp you earn from playing the game. It just takes longer.
The "beta" is about 3 hours of gameplay. It will take you through the first major quest arc. Then you just end up grinding up mobs to gain levels or roll another class. You end up about level 10 at the end of the beta quest arc. It is less of a beta and more of a demo.