Sonic Boom: Shattered Crystal (known in Japan as Sonic Toon: Island Adventure) is a 2D side-scrolling platformer developed by Sanzaru (under supervision by Sonic Team) and published by Sega for the Nintendo 3DS on November 11, 2014 in North America, on November 21, 2014 in Europe, and on December 18, 2014 in Japan.
Alongside Sonic Boom: Rise of Lyric for the Wii U, the game was built for the Sonic Boom French-American CGI-animated television series (a spin-off of the main Sonic the Hedgehog game series). It later received a sequel in 2016, titled Sonic Boom: Fire & Ice.
The game follows a rag-tag group of heroes (Sonic the Hedgehog, Miles "Tails" Prower, Knuckles the Echidna, and newcomer Sticks the Jungle Badger) who must rescue Amy Rose from the villain Lyric. Players can switch between the four heroes, each with their own special abilities.