I need help playing fan games since most games are .xdelta, how do you play xdelta on it??? I just wanna know

xdelta files are patch files, you need to apply them to an unmodified rom to get the rom for the hack you wanna play. in the case of nsmb hacks, you typically wanna apply patches to american roms. heres a website that lets you patch roms online, and heres a thread with some more info on using xdelta patches.

Thank you so much