Space Vapour: Since his Wing Commander days, Chris Roberts has always been one of the most ambitious game designers in the industry. Thanks to Star Citizen's undeniable crowdfunding popularity, he may have created one of the most successful games in history – without spending a dime of his own money, or even delivering a finished product yet.

Just one year after reaching $800 million in its unrelenting funding spree, Star Citizen has now crossed yet another significant milestone. The overly ambitious space trading and combat simulator, developed by Cloud Imperium Games, has officially raised more than $1 billion from enthusiasts and early backers. Game director Chris Roberts, meanwhile, is still talking about stretch goals and plans to add more content to his unfinished gaming universe.

Star Citizen's funding tracker currently lists 6,547,075 backers who have "donated" hundreds of millions of dollars since 2012. CIG states that the game's scope is determined directly by backer support, meaning more money funds more in-game content. The crowdfunding campaign started in December 2012, though CIG stopped publishing additional stretch goals after earning more than $65 million, a couple of years later.

In a recent interview, Roberts credited Star Citizen's success to gamers seeking an endless adventure in complex, detailed online worlds. His multiplayer universe can allegedly offer things that other entertainment products cannot, because traditional publishers – or even private equity ventures – are mostly focused on building finished products.

By contrast, Star Citizen is going to remain essentially "unfinished" for quite some time. Roberts and his team at CIG are now working toward the game's first "1.0" release, at which point it will no longer be considered in alpha. After that, the team plans to keep building the universe and adding new content, so that those adventure seekers can enjoy losing themselves in the space sim experience for years to come.

Roberts compared Star Citizen to World of Warcraft, an MMORPG that has been running for more than 20 years. The original WoW was released in 2004 and has since been reworked, expanded with multiple expansion packs, and graphics upgrades.

Star Citizen is also building its unprecedented crowdfunding legacy with some questionable marketing campaigns. Just before reaching $1 billion in funding, CIG introduced a limited "concept" sale for the Anvil Odin capital ship, with no actual 3D content yet available in the game. Backers had to pay $5,000 and write an essay to apply for a spot in the exclusive Odin Founders Club, with the actual game experience to follow at a later date.

One of the Anvil Odin "applicants" said he had already spent many hours with Star Citizen's alpha, and was happy to put that kind of money back into the game. CIG is also working on Squadron 42, a single-player experience set in the Star Citizen universe, which is reportedly targeting a 2026 release for a "finished' game.