The phrase "sonic speed" means going really, really fast, like the speed of sound.
Sentences with «sonic speed»
Experience super sonic speed as you grind, slide and boost as Modern Sonic. (amazon.co.uk)
Several zones of Sonic speeding across an entire game, no stops, just a sweet blue emotional haze. (segadoes.com)
The video unveils gameplay of Classic Sonic speeding through Casino Forest, a stage which gives a nod to the iconic Casino Night Zone from previous Sonic games. (nintendofuse.com)