Originally Posted by Qwertystop
GUys. Guys. Guys.
I just found the file in Cave Story that defines whether or not different modes have been unlocked.
It's a text file. With the code explained right there.
Oh man, I remember finding that! Actually, I think it's still on my desktop or something. That was fun.
Regardless, I've played through it four times already. (By which I mean, I've played all the way up into the Sacred Grounds, which I have yet to beat.)