Spider-Man 2 Codes -

All special moves:
Have the Game Boy Advance game Spider-Man: Mysterio's Menace in the cartridge slot to unlock the all special moves.

Faster recharging special meter:
Successfully complete the game (Chapter 14) once to receive a faster recharging special meter.

Unlimited special meter:
Get a 100% game completion to unlock an unlimited special meter. 

Chapter 3: Special move upgrade:
Continue to the right until you reach a train station. Then, look under the electric trap.

Chapter 7: Special move upgrade:
When you start the chapter, move to the left and get to the top of the building that is farthest to the left. Super jump, then web sling to the right at the top of your jump. Avoid the helicopter and collect the upgrade.

Chapter 9: Special move upgrade:
The upgrade is located very high above the movie theater. To reach it, super jump from a high ledge and swing around until you see it.

Chapter 11: Special move upgrade:
Keep going right though the level until you reach the train station, over the electric trap. Keep swinging while holding up Left and Right until you reach the hidden power-up.