Tribes: Ascend, the free to play shooter, is great for the very idea that any weapon or upgrade that can be bought with cash can also be purchased by simply playing the game. Granted, by the time you play Tribes: Ascend long enough to unlock every weapon and upgrade, you might be cashing in your retirement check and playing on virtual reality machines.
As part of the June update, Hi-Rez Studios is greatly increasing the rate at which unlocks are obtained. The new system will operate in a manner familiar to sandbox MMO fans: Each piece of equipment has its own experience bar which increases as you use it. To speed up the process even more, you still obtain experience and GP that can be spent on unlocking further upgrades even faster.
Now that Tribes Ascend can (reasonably) be played for free, there is no reason not to jump in and start killing the deserving Sandrakers.
MMO Fallout 