Startrail One Stroke

Choose a numbered star to begin. Then choose neighboring stars to cross each bridge exactly once. You may visit a star again, but a used bridge is closed. A stranded route needs Undo or Restart. Number keys 1–9 select stars; U undoes, R restarts.

A route exists when the connected graph has zero or two stars with an odd number of bridges. With two, start at one and end at the other. Route hints suggest a move without making it.