First off, let me know how that Nightmare Busters is. I almost bought it a couple of times, but have held off.
Second, there are several places online that make Repros of unreleased games and Homebrews. I grabbed a few of these at Retropalooza a couple of weeks ago from 8-Bit Evolution. I got Wily Wars and Fix-It Felix Jr. for Genesis and Drac's Night Out on NES. I like the idea of new stuff coming out 20 years too late. I'll still grab it.
In the event you return to this thread, Nightmare Busters finally arrived. It's a pretty sharp package--full color manual, beautiful SNES-style box, and a solid cartridge that worked as well as any official SNES game. Very impressive. The game itself is heavily action-oriented, and the closest thing I can think of off-hand is Mega Man inspiration. Move from left to right "shooting" enemies with various attacks, and launching powerful screen-filling magic attacks when you have the opportunity. It runs smoothly, looks good, and is pretty hectic.
However, it spawns enemies like a Ghouls n Ghosts title--as in, willy-nilly all over the damn place, so it can be quite chaotic. There are a few platforming issues I have (jumping over fire in the first level feels awkward), but the game overall is actually pretty fun and extremely challenging. Picture Super Ghouls n' Ghosts, but with lots of shooting mechanics and screen-clearing magic that made me think of Golden Axe.
Overall, a charming purchase, and I'm glad I got it.