Extra costume/outfit colors
Hold start when you've highlighted the character, then press any of the 3 punches or kicks to get a hidden costume. You must have beaten the game with a character to use any of his/her hidden costumes. To use the secret costume/outfit and press LP, HP, and MK. (beating the game with the character is not required for this costume)

System Direction page 8
Win the game with five characters with the System Direction set to "Normal".

System Direction page 10
Win the game with fifteen characters with the System Direction set to "Normal".

Fight as Gill
Win the game with every character with the system direction set to "Normal". Gill will appear in between Yun and Yang at the character selection screen.

Extra options
Complete Arcade Mode as Gill.

System Direction page 9
Win the game with 10 characters with the System Direction set to "Normal".

Fight Q in Arcade Mode
To Fight Q in Arcade Mode don't lose a single round in Arcade mode up till the end of Stage 8. If you die, you cannot rematch him.

Alternate difficulties in Sean's bonus stage
Hold Down + LP + MK + HP when reaching Sean's bonus stage for a harder difficulty. Hold Up + LK + MP + HK when reaching Sean's bonus stage for level 5.

PS2 Cheats for Street Fighter III: Third Strike

Street Fighter III: Third Strike cheat codes

Street Fighter III: Third Strike cheats