If i could pick one free to play game, which other game developers should take an example from, that would be Warframe. Massive content, great story behind. I remember how they start, when i played with friends, there was literally 1 map with 3 warframe's ( playable characters). This game start from nothing, extended contet and story which now is on high level. One of the best, if not the best Game F2P, totally worthy of your time to try. I recommend and support.