Google is set to add new games categories to its Play Store in February next year, with developers able to submit suitable apps now.

The new choices include “simulation”, “role playing”, and “educational”.

Until the new categories go live in February 2014, the existing category selection for an app will not change.

The company also announced a Google Play Games plug-in for Unity, to enable developers to more easily integrate game services into apps developed using the Unity cross-platform game engine.

The initial version supports sign-in, achievements, leaderboards and cloud save in Android and iOS apps, and is available from the Play Games project page on GitHub, alongside documentation and sample code.

Finally, it announced the open-source release of LiquidFun, which it described as “a new C++ 2D physics library that makes it easier for developers to add realistic physics to their games”.

Being written in C++, Google said that any platform that has a C++ compiler can benefit from the LiquidFun library.

It has provided a method to build the LiquidFun Library, example apps, and unit tests for Android, Linux, OSX and Windows platforms.