Phineas & Ferb: trouble on the streets

Plot
Dr Robotnik Tricks Phineas and Ferb with a disguise. Phineas builds a portal.

Characters

 * Phineas
 * Ferb
 * Perry
 * Isabella
 * Sonic
 * Tails
 * Carol
 * Heinz Dofensmritz
 * Irving
 * Dr Robotnik
 * Dr John (Mentioned)
 * Zoery (Mentioned)