I've noticed today after playing this version of Night Slashers that you can't change the game's difficulty. That said, I'm not sure what difficulty it's set on but I can say it is not on the Hardest difficulty.

Another thing to note is you can't change the button control scheme they've set up as far as my knowledge goes; a button is attack, b button is jump, and y button is mega crash.

Also, you cannot change the version settings or censor blood color. This version is the English/international version and blood color is red.

After poking around with it on MAME - it does seem pretty accurate, but I guess that's a pretty low bar these days. It's a shame about the settings and button mapping not being accessible though.