SONIC PICO PARK Characters
The SONIC PICO PARK official site names PICO CAT, Sonic, Tails, Knuckles, and Amy. Every playable character can Spin Dash.
The official SONIC PICO PARK site names PICO CAT, Sonic, and Sonic's friends including Tails, Knuckles, and Amy. Steam says every playable character can use the Spin Dash. That move is not limited to Sonic.
Those two pages do not publish a move list for each character. This page does not add flight, glide, or carry rules they do not state. How a stage is cleared is in how a stage ends. Which machines can play together is in crossplay.
PICO CAT is the series character. The official site describes this entry as PICO CAT racing with Sonic for Sonic's 35th anniversary. The series sales figure on that page, over 8.5 million copies, is for PICO PARK as a series, not for SONIC PICO PARK alone.
Related guides
SONIC PICO PARK Crossplay
SONIC PICO PARK online play supports crossplay. The official site lists Switch, Switch 2, PS5, Xbox, and PC. One PC can bring up to 7 local players online.
SONIC PICO PARK: How a Stage Ends
A SONIC PICO PARK stage ends when every player reaches the goal plate on the right. Steam supports 2 to 8 players, locally or online.