Step-boom[derived from Japanese] is an item which appears in the Top Ride mode of Kirby Air Ride. It appears randomly during standard races, dropping onto the course. When touched by a racer, the mine appears on the back of the vehicle. Once the racer deploys it, the mine will sink into the ground, being marked only by a tiny dot on the track. There it will remain until another racer moves over it, where it will activate, knocking them back and releasing confetti in the process. Unlike most other items, the racer who laid the trap can also be hit by it.
The Step-boom can be dropped prematurely by performing a Quick Spin, or if the racer is attacked or enters a stage hazard. It will also disappear on its own if not used within 8 seconds.
Names in other languages
From fumu (踏む, "to step on") and don (Japanese onomatopoeia for explosion).