I wrote a short supplement for The Nightmares Underneath that has Powered by the Apocalypse rules for players to use, for those of you who prefer that style over the old school D&D-ish rules. It is called A World Full of Nightmares, and it includes:
• a set of basic moves;
• new rules for harm and disposition, experience, and money that are more like Apocalypse World;
• simple character classes with simple special abilities (but you can add special moves from Dungeon World or Class Warfare if you like);
• conversion rules for the nightmares curses;
• a simple GM section;
• a new more-narrative-y system for creating incursions that you need a deck of cards for.
Find this game at Lulu.