Sonic Frontiers is a 3D platformer and action-adventure game,[1][2] and the first Sonic the Hedgehog game to feature an open world.[3] As Sonic, the player explores the Starfall Islands, which comprise various biomes including flowery fields, forests, ancient ruins, and deserts.[1][3] Multiple writers compared the open-world design to The Legend of Zelda: Breath of the Wild (2017).[4][5][6][7]