I recently learned that Sony made three of their Station Pass games free again. I'm talking about Infantry, Cosmic Rift, and Tanarus.
Infantry is pretty good, it was worth paying $3 a month for it when it was new. Of course, it was free when it was new and then Sony started charging for it, but it's a pretty good game. I'll say more about it soon. Cosmic Rift is basically Infantry IN SPACE with LOOSE CONTROLS and STAR FIGHTERS!!! It's not a great game, and almost nobody plays it. Tanarus is some sort of tank game. Maybe? I don't know, I never played it.
The Infantry engine is a top down shooter that allows for inventory management. They took this engine and created a few different "zones" which are essentially servers running fairly comprehensive mods. Within a zone you can play on the public arena(s), or you can create your own. The Sony servers are the only ones I have experience with, so I'll talk about those.
In depth zone descriptions:
The most popular zone is the Infantry:RPG hybrid, where you gain additional proficiencies is weapons by killing people. You band together in teams of up to 10 to make this task easier. It's much more new player friendly than it used to be, but it still takes a fair bit of hard work to start paying off.
Usually second in popularity is the Skirmish zone. Here, the extent of character development is simple. Pick a class. Then you get assigned to one of two teams, and you try to kill the other team. Currently, that's all there is to this zone, but I used to see other maps with capturable objectives and drivable vehicles.
Then you have Infestation, which is probably the best zone. Players are divided into two teams, the marines and the Skrall. The marine objective is to board an alien infested space station to recover several important objects. Only sergeants can carry the objectives. The Skrall objective is to prevent the marines from succeeding, all while gorging themselves on delicious people meat. The marines have superior long range fire-power, but are frail and squishy. The Skrall have brutal close quarters ownage, but lack a mid range option. The map is full of tight corridors with air-vents for the Skrall to crawl in and doors for the marines to die when opening.
They used to have a bunch of CTF zones, which were all pretty good. You would divide into teams, pick a class for your general archetype, and then buy equipment. There were generally two or three workable themes for each class. Currently though, they only have a zone for CTF extreme. Which means private teams are available, teams are capped at 10, and the map is way too big for the number of players.
At this point, you start hitting the dead zones. You might see a group of 4 in these zones once a week. The first such zone is Hardcorps, weapon deadliness turned way up to strongly encourage use of cover and flanking. Then you get Boom Ball, which is kind of like, uh, pong with rocket launchers. There's also GravBall, which is like soccer on hover bikes in an obstacle course with rocket launchers. And finally you've got Soccer Brawl, which is like soccer.
The player base ranges from a few loud mouthed morons in every zone to a majority of mostly silent players, who only speak for teamwork's sake, to a few veterans willing to help out. Teamwork is surprisingly prevalent, even if it's mostly the sort of teamwork where people stick together just to avoid dying.