SNES Locked Games
Credit to consolemods.org
Regardless of the cartridge slot region free mod, there are games on the SNES that are region locked at the hardware level within the cartridges via the CIC chip and the PIF chip of the console. It is a misconception that you will be able to play all NTSC-J games on an NTSC-U unit and vice versa with the cartridge slot mod.
It is possible to bypass the region check by disabling the CIC chip, but some titles may not function as some do check if the CIC chip has been disabled. There are mods available to install that can make console region free software wise.
This is a list is subject to change as further information is found.
NTSC-U Region Locked
ABC Monday Night Football
The Adventures of Batman and Robin
The Adventures of Dr. Franken
Animaniacs
Ardy Lightfoot
Ballz
Biker Mice from Mars
Captain Commando
Castlevania: Dracula X
Donkey Kong Country
Donkey Kong Country 2
Donkey Kong Country 3
EarthBound
Kirby Super Star
Kirby's Avalanche
Kirby's Dream Course
Kirby's Dream Land 3
Knights of the Round
Mega Man's Soccer
Metal Warriors
Ninja Gaiden Trilogy
R-Type III
Sparkster
Super Mario All-Stars
Super Mario All-Stars & Super Mario World
Super Mario World 2: Yoshi's Island
Super Metroid
Tetris & Dr. Mario
TwinBee: Rainbow Bell Adventure
Ys IV: Mask of the Sun
NTSC-J Region Locked
96 Zenkoku Koukou Soccer Senshuken
Ace o Nerae!
Bushi Seiryuuden: Futari no Yuusha
Akumajou Dracula XX
Super Donkey Kong
Super Donkey Kong 2
Super Donkey Kong 3
Dragon Ball: Super Butouden 2
Dragon Ball: Super Butouden 3
Mother 2
Hoshi no Kirby Super Deluxe
Hoshi no Kirby 3
Rockman's Soccer
Ninja Ryukenden Tomoe
Panel de Pon
Popful Mail
Seiken Densetsu 3
Super Mario Collection
Super Mario: Yoshi Island
Umihara Kawase