Unlock everything at once

To unlock all bonus art, cast, tips, and music files for all games, plus unlock weapon select in all three GnG games (use L/R on Right Analog Stick to switch weapons), input the following code on the CCC Title Screen:

L1, R1, Up R-Analog, Down R-Analog, L1, R1, Up L-Analog, Down L-Analog, L1, R1, Up D-Pad, Down D-Pad

You will see "All Locks Open" at the top of the screen if you successfully input the code. Thanks to mjb659.

Contributed By: jeffx.

Unlockables

Contributed By: KFHEWUI.

Weapon selection

Hold the designated button at the beginning of each levels start screen to activate whatever weapon you wish for.

Codes on left side of " / " are for player one to enter , codes on right side are for player two to enter

Contributed By: whoisthisgit.

Turn into a Frog

Duck and then shoot a tombstone 15 times in a row and an angel character will appear. This angel will fire a bolt at you. Let it hit you and you'll become a frog.

Contributed By: Retro.

An interesting bug

When you're on level two, make sure you have a horse when you kill Roy Knife. Once he is dead, walk over his corpse and your horse will be killed. Roy raises from the dead as a sort of indestructible zombie. You can shoot him as much as you like, but he won't die. In this way you can play until you get tired of it.

Contributed By: Saikyo Mog.

Numbers

This code is entered during a demo battle as soon as the CPU players start fighting.

Contributed By: overstayer.

Skip fights in arcade mode

Although arcade mode is usually only 1 player, to avoid skip the level, another controller is needed. If you are stuck in a particular level or simply want to skip levels, first, select your character. Wait till the console loads the battle. When the fight has just begun, press the start button on controller 2. Something around the lines of "here comes a new challenger" will appear on the screen and the music will change. You will then be taken back to the character screen. With the second controller, select the person that you were about to fight with and wait till the battle begins again. Then with the first controller, kill the other fighter (since he is controlled by controller 2, he won't do anything unelss someone operates him, so you can easily get a perfect). Once you have beaten him in both rounds, wait tillthe character screen and the map comes up again and the plane in the map will move to the next level. In other words, you have just skipped that level. This will work all the time except when the computer is playing as M.Bison

Contributed By: ajayjumbu.

Game Stats Since Last Reset

This is a simple code to check the game stats since the last reset. Enter it, and two rows of numbers will appear like this:

0000 0000 0000 0000

000 000 000 000 000 000 000 000

The first top number is unknown, the second is the number of coins entered on the P1 side, the third is unknown, and the fourth is the number of coins entered on P2 side.
As for the second row, it's simply the number of times Ryu, E. Honda, Blanka, Guile, Ken, Chun-Li, Zangief, and Dhalsim have been used respectively.

Note: This code also works in all revisions as well as the "sequel," Street Fighter II: Championship Edition.

Contributed By: Joseph Collins.

Bonus Ending

Contributed By: BongoGoku.

Codes

Contributed By: ACE Spark.

Extra difficulty

Beat the game on normal mode to unlock professional mode

Contributed By: dieourumov1.