Race with ice!
— Sonic Boom: Fire & Ice announcement trailer
Ice Mode can be triggered by harnessing Ice energy. In Team Sonic's case, they could harness Ice energy after their Communicators absorbed some from a fissure. When utilizing Ice Mode, the users envelop themselves in a freezing blue aura. Anything they come into contact with are then instantly frozen solid. Even the user's steps will cause ice to sprout from the ground or from any rails the user is grinding on. This effect can be channeled through weapons as well, like Amy's Hammer and Tails' Blaster. As a side-effect, the user constantly leaves a blue and white color trail.
Ice Mode is one of the core gimmicks in Sonic Boom: Fire & Ice. While Ice Mode is active, the player can freeze blocks of water with snowflake icons that they or their attacks touch, creating solid blocks for the player to walk on. The player can as well freeze Water Spouts to create Rails. Additionally, some enemies that are hit by attacks while Ice Mode is active will be frozen in ice before they blow up. To melt and counteract the Ice, the player has Fire Mode. Otherwise, any frozen water will re-thaw after a couple of seconds.
To use Ice Mode in gameplay, the player can simple toggle between it and Fire Mode using the L or R button. When Ice Mode is active, the Nintendo 3DS's lower screen will show ice crystals and snow around the lead character's icon.