Ray the Flying Squirrel

is an isometric platform game in the Sonic the Hedgehog series, released by Sega for arcades in 1993. The game supported three players playing simultaneously, and possessed a unique track ball set up for moving on-screen characters. The only other control input was a single button, allowing the player to perform a jumping attack. The use of the trackball has subsequently led to great difficulty in emulation efforts, with Yuji Naka stating it as the reason for it not being included on future compilations or rereleases, such as Sonic Gems Collection.