Easter Egg There is an easter egg left in the game by the game developers. At the beginning of the game, it is possible to see the final stage. You can see Mary Jane and Mysterio, but the walls prevent you from getting to them inside the building.

If you run across the top of the building rather than jumping into it, you can find a helicopter on the roof. Standing in the middle of the rotors will cause it to take off. If you are standing on the helicopter when it's at the second highest elevation it reaches, you'll hear a switch. This changes the screen below you to the final one.

Black Thunder Skip

Using the easter egg above, it is possible to use abuse it to reach Mysterio.

From the beginning, jump across the ceiling to the helicopter. Stand in the center of the rotors, and begin walking to the left. When the helicopter is at its peak, jump off the left side and shoot a couple of webs to help you get across the black screen.

While he is in the air, but before he reaches the left wall, tap right to face away from the wall. This will prevent him from curling into a ball on impact.

If Spider-Man is completely vertical on the left edge of the screen as he enters the next, he will appear completely inside the left wall of the building. Because there is no "floor" to stop him, he will continue falling through the wall until you input some sort of action that extends him outside the wall. Hit the switch and catch to ledge to knock Mysterio into the flames below, making sure to web him so he can't move.

[EDIT]: Added simple technique for staying vertical in Black Thunder