Free Infantry, a privately hosted server for the game known as Infantry Online, is basically a top down multiplayer 2D shooter. The games been taken far beyond the point of "private server" in that the game engine itself has been heavily modified and that the actual gameplay at hand is, outside of core concepts, completely unique to the community.
During the time when Sony Online Entertainment charged for players to retain names and stats in Infantry Online, Free Infantry had upwards of 200 players at peak times. In these dismal days, 50 is a miracle.
It would also be very important to note that "SoE" knows full well of Free Infantry, even to the point of discussing it openly on their own forums, and little to no evidence has been shown that they care the least bit about this servers operation provided the content is our own.
What am I telling you all this for?
Well to put it simply!
Go to FreeInfantry.com
Download the game
Create an account from the launcher
enter a zone with players (which likely will not exist anytime between 1AM and 1PM EST) - and play the game.
Warning in advanced - While very solid, the remaining community is about as friendly as a rabid zombie badger who just plain old doesn't like people.
ENJOY!