Crossplay

Is Wonder Boy III: The Dragon's Trap crossplay?

Crossplay does not apply to Wonder Boy III: The Dragon's Trap: it has no online multiplayer.

A direct sequel to Wonder Boy in Monster Land, you wander through the lands using multiple forms that each have different abilities. Each defeated boss unlocks a new form that has to be used to advance to a new area, while shops give you access to new equipment for money.