Alien Swarm, released just last week (7-19-10) is a tactical overhead shooter released by Valve (Creators of the Half-Life Series). The game was actually created by a group of community mod developers hired on by them.
Has both single and four person co-op play. The multiplayer system works by steam powered matchmaking system where one of the four players is the host and others looking to play the same level join while in briefing. Four classes to choose from: Officer, Medic, Technician, and Weapons Specialist. Two variations of each is offered for a total of 8 characters. Each with their own stats that enhance their performance in different ways. Once a character is taken it cant be reused by another player in that game. That means you'll never have all of one class. Even two of the same class in one game is typically a bad strategy. Another impressive element is the leveling and achievement system.
- Level cap is 27 in which you are set back to level 1 with a promotion.
- There are 64 achievements and over 40 weapons you can earn while leveling.
What's going to make this game great over time is the fact that they released an SDK for moders to build on. So, look forward to an endless supply of extra levels and game modifications as it continues to grow. It looks impressive visually which no doubt makes you concerned about system requirements. It's pretty minimal actually. See the Alien Swarm System Requirements page for exact details. You can join Steam for free and use the store to look up the game Alien Swarm to download it on your account. In my opinion, it reminded me a lot of Starcraft and Starship Troopers at times.