Team Fortress 2, a colorful team-based online first-person shooter game, will be free to download and play and will generate revenue through in-game transactions, game developer Valve announced today.

That means the game will use the “freemium” model, which is usually designed to tease players with a free game and then encourage them to buy more powerful items. Team Fortress 2 is the first high-profile console and PC first-person shooter (FPS) game to go free-to-play. Players will be able to buy “hats” for their characters, along with other cosmetic items and new guns. But Valve was quick to indicate that free players would not be at a huge disadvantage to players that pay for virtual goods.

“All game modes, classes, and maps are available. Nearly every weapon is available through achievements, drops, or crafting,” the company said in the announcement.

Team Fortress 2 is a multiplayer FPS game that lets players team up in huge capture-the-flag and king-of-the-hill style matches. Players can choose from one of several classes that all fulfill certain roles, like the speedy scout who is good for carrying intel (the game’s version of a flag) or the medic, who can heal and supercharge friendly players. It’s one of Valve’s unusual stunts to try to pick up additional gamers, even though the game is already incredibly popular.

The game is one of only a few on the market right now that thrives on team-based gameplay rather than single-person heroics. Most multiplayer FPS games include team-based deathmatch games — where the team with the largest number of kills wins — but don’t encourage a lot of teamwork in pick-up and casual matches. In Team Fortress 2, teamwork is essential — even for casual gamers who just want to play a quick match during a lunch hour.

It’s also an unusual FPS game because of the artistic direction. Instead of ultra-realistic graphics like those seen in the Battlefield and Call of Duty franchises, the game looks like a cartoon brought to life. Characters have exaggerated features, such as the heavy and his massive minigun and huge muscles. They all have personality quirks too — for example, the sniper is built off a Crocodile Dundee-style Australian hunter.

But despite its quirks, Team Fortress 2 is critically acclaimed and was a large factor in the success of the Orange Box, a collection of five games that Valve released in 2007. The collection included Half Life 2, along with its sequels Episode 1 and Episode 2, Team Fortress 2 and the smash hit Portal. The Orange Box is currently the highest rated PC game of all time on review aggregating site Metacritic.