I've found that the attract scene mode crashes under the new engine, so it's temporarily removed (it does the cutscene intro then after the Simon whips, it loops back to title screen menu, skipping the troubled demonstration scene).
But if the button works and you can play, that's a step in the right direction:
https://www.mediafire.com/file/lc2sxjkbl34uiqh/CastlevaniaAGA_WHDL_Nov6.lha/file