The Thunder Cloud feature of Mario Kart Wii gives the player off-road capabilities , then the player has to collide with other racers to pass the Cloud onto them .
The Mega Mushroom temporarily grows the player to an enormous size and allows them to flatten opposing karts , the POW Block causes all racers ahead of the user to spin out and drop their items if used , and the Thunder Cloud gives the recipient a spped boost , but the recipient has to get rid of it before the item shrinks him to a tiny size .
Mario Kart Wii