Spil Games said it has completed the first steps toward true cross-platform gaming on mobile browsers. The features are an important milestone in Spil’s quest to create a truly unified cross-platform gaming experience.

Spil Games says the future of mobile social gaming will be in the browser not in “native” apps written for a particular kind of mobile hardware, such as Apple’s iPhone. Browser-based games can run across platforms and allow players to play on any platform they want. By introducing social features to browser games, Spil Games is making the browser platform more attractive.

Currently, most mobile games are native games, since that allows them to run as fast as possible and take advantage of specific features of a phone’s hardware. But Spil Games is supporting HTML5, the new proposed format for the lingua franca of web applications. Spil Games first announced its support for HTML5 in August, 2010, and it has promoted HTML5 game development through a monthly contest. The company was also early in coming out with browser-based mobile versions of all of its web sites starting last September.

The Spil Games mobile platform will let users update their social network status with their game achievements and save their high scores. Developers can implement these social features, typically seen only on PC games or app-based platforms, into their browser-based mobile social games. Developers can also write their apps once and have them run on multiple devices, saving on development costs.

Peter Driessen (pictured left), chief executive of Spil Games, talked about the new features for the first time at the GamesBeat 2011 conference in San Francisco today. HTML5 games allow developers to update and improve their games instantly, without going through an approval process. And they allow mobile users to play games on whatever device they choose.

The Hilversum, Netherlands-based company has 130 million unique visitors a month for its web and mobile games. It has more than 4,000 online games that have been developed either internally or through relationships with third-party developers. Those games are available on girl-oriented sites such as GirlsgoGames.com, Agame.com, and Gamesgames.com. Spil games is present on social networks through its Zapapa game application.

Spil Games was founded in 2004 and has 300 employees. Investors include Van den Ende & Deitmers.