Cross-platform multiplayer Cross-platform co-op Windows Mixed Reality Ray Tracing 60 fps+ 120 fps Optimized for Xbox Series X S Cloud enabled Smart Delivery Console Keyboard & Mouse PC Game Pad Xbox Live Cross-Gen Multiplayer More. Cross-play is the ability to play an online video game across more than one platform – meaning someone playing Fortnite on Nintendo Switch could be on the same server as someone using an Xbox. Unity is a cross-platform game engine developed by Unity Technologies, first announced and released in June 2005 at Apple Inc.' S Worldwide Developers Conference as a Mac OS X-exclusive game engine.As of 2018, the engine had been extended to support more than 25 platforms.The engine can be used to create three-dimensional, two-dimensional, virtual reality, and augmented reality games, as well.