I'm holding Back + High Punch + High Kick + Block + Run after selecting a male ninja like the code says, but it never sets me to playing as Chameleon. I've not no idea what's going on. Is chameleon just not in this version?

I just hold HP+LP+BL:until the round starts and it works..... I've even done it after playing 1 round as a male ninja, then switch to Chameleon by holding the buttons.

Thank you! I too could only find information about holding BACK+HP+HK+RUN+BLOCK and it never worked. I assume the combination for the GOG release was changed to HP+LP+BLOCK for some reason (probably to make it simpler?). I'm glad you shared it here, because otherwise I would never know :)