Runbow out now on Xbox One. And is currently free for Xbox Live Gold subscribers until August 15th. The game is a platformer but features a variety of different modes to play and impressively supports up to eight players at once on the same screen in local multiplayer and nine when playing online.
The official description:
Get Ready to Runbow! Runbow is a fast-paced action party game for up to 8 players locally and 9 players online. Platforms and obstacles appear and disappear with each swipe of the background color, so if you can’t see something, IT DOESN’T EXIST! Players can go head-to-head in Run, Arena, and King of The Hill, or hone their skills on their own in Adventure or The Bowhemoth.