From Sonic Retro
Thunder Shoot is the basic attack move of Flight Formation in Sonic Heroes, used by Tails, Rouge, Cream, and Charmy. Flight Formation sees the Teams arrange themselves in a three-man tower, with the flight character keeping them aloft. Pressing sees the leader punt one of their allies forwards like they're kicking a football, (somehow) conferring upon them a crackling shield which sends them homing in against enemies.
The move's damage varies depending on the flight character's level, from just stunning an Eggman robot to exploding a whole set of them one after the other. Either way, it will always knock the opponent out of the sky, and as such is often the only way to down an otherwise out of range flying enemy. Upon the third level up, Thunder Shoot acts like a magnet that can pick up rings.
Since a flight character has two friends underneath him, in Heroes this move can be used twice in quick succession.