Ticking the Ironmode box then playing Freeride will initiate the hardest difficulty in the game.
In Ironmode Freeride the player cannot hit a single block, otherwise the game will end.
Ironmode Freeride Ability Edit
Sometimes your character will hit a block and it will not end the game, this is because the character hit the block with 1 of 2 fins on the Freeride model.
Successfully hitting blocks with the fins of the Freeride model will delete the block, allowing the player to navigate through tighter spaces than other characters.