The search giant said on Thursday that it would host a game festival in San Francisco on Sept. 24 focusing on independent developers who build apps on Google’s Android mobile operating system.

Interested participants can submit their games to Google (GOOG) by August 14, and Google will determine which games will be presented at the conference. Public companies are not allowed to participate, Google said.

In order to participate, coders must be based in the U.S. or Canada and must publish their games on the Google Play Store.

Get Data Sheet, Fortune’s technology newsletter.

Google will choose 30 games to showcase and pick three winners, with prizes including Google Tango devices that are outfitted with 3D motion-tracking sensors that let coders build more immersive apps. Additionally, winners could receive Google ad campaign support that could let them earn more cash through their apps with more free Google ads.

Google is also encouraging developers to build virtual reality and augmented reality apps using Google’s Daydream VR tool kit or Tango software toolkit.

Like Facebook (FB), Samsung, HTC and other companies trying to build a VR business, Google needs developers and companies to create VR games and movies for its devices. The more compelling media available for VR headsets, the more likely people will want to buy them.

For Google’s new conference, however, coders are not allowed to submit VR games they may have made using Facebook’s Oculus VR tool kit or other competing VR developer tools.

For more about Google, watch:

In May, Google announced its Daydream VR software kit as well as hardware reference designs so other companies could build VR headsets based on Google’s blueprints. The search giant will also sell its own VR viewing device and related controller that will be more expensive than its current low price Cardboard headset.