Hey, guys! Thank you!
And I did it too!
Police Precint - Stage 2You are there at the police station giving the police a beating and one of them drops his stun gun. You just have to destroy the arcade in the next room and you will automatically go to a retro level and fight Jack.
Old Pier - Stage 4In phase 4, Velho Cais, in one of the parts there will be a store written "Arcade" in neon, literally. You will fight with cops and one of them will leave his stun gun for you! :)
That done, just get the stun gun and enter the arcade store, give the machine a shock and go to the fight in the retro phase. You will fight with Zamza.
Underground - Stage 5This was a phase that always ended up breaking the arcade with the taco = (. The machine is near the bar under the lamp.
This time I got far away from the machine, killed the world, took the stun gun and went to fight with Abadede.
Art Gallery - Stage 8When you leave the art gallery, you will enter a room full of golden chickens. In this room there is an arcade in the corner and there is a stun gun on the floor in the lower left corner, there is not a single enemy around to get in the way.
Just take the gun and shock the arcade and run to fight Shiva and Mr. X.