Killer Instinct was the first Xbox title to support cross-platform play between Xbox One and Windows 10.
Microsoft used the fighting game to demonstrate Xbox Play Anywhere-style cross-device integration before the program became broadly associated with later releases. Players on Xbox One and compatible Windows 10 PCs could compete across the two platforms, while the game connected to the Xbox account ecosystem.
The 2013 Killer Instinct reboot was developed by Double Helix Games, with later development handled by Iron Galaxy. It launched as a free-to-play title with a rotating or separately purchasable fighter model, depending on the edition and period.
The game is sometimes confused with Microsoft's later cross-play announcements for Gears of War 4, Forza Horizon 3, and other titles. Those games helped popularize the feature, but Killer Instinct was the earlier Xbox One and Windows 10 example cited for cross-platform competition.