We first heard of Gambitious way back in April and now they've finally launched. The service is most easily understood as Kickstarter if Kickstarter were only for promoting game projects. Although they are currently based in Europe, and posting requires some EU-specific requirements, they are hoping to expand their service to the US soon. Earlier this month Kickstarter shared how much games generated for the site so they may not take kindly to a newcomer.
Why was Gambitious launched?:
"Gambitious is the first professional crowdfunding platform exclusively dedicated to the games industry. We are here to help independent game developers and even publishers reach the widest audience with their proposals and to attract the funding they need to complete the project and to bring it to market."
It will probably help them in the long run to be dedicated solely to games, but it may take a while before people find it a viable alternative. Everyone still knows the name Kickstarter thanks to massively successful projects like Double Fine's. Right now there are a handful of game projects running. The spotlighted title is Mushroom Men: Truffle Trouble which is currently 1.3% funded.
Is a game-specific crowdfunding source something you might use?