PCERF is programmed by MottZilla. It searches PCE roms for a code sequence
used in US software to stop the game from running on Japanese consoles and
patches this code sequence to allow the games to run normally. I wrote it
after finding other programs that attempt to do this generally break the
game while doing it. Notably Neutopia would run but would crash when using
one of the items and when hit by enemies you didn't react normally.

I have not extensively tested this program with every single US game. But
they all seem to use the same bit of code that usually is right at the very
beginning of the program and usually that is all. Give it a try with your
programmable HuCard of choice.

I have briefly tried the following games.

Bloody Wolf
Bonk's Adventure
Neutopia
Raiden
ShockMan
Side Arms - Hyper Dyne
Splatterhouse

The games listed all atleast started up into the first level. I think it
is likely they will play fine.