What a fun and amazing game idea for the NES- a Murder Mystery using classic NES characters and scenes! I've just finished it and had a blast. I've recommended it to all my retro-enthusiast friends :)
BTW, I'm not sure what happened with the boulder bit as I didn't see anything moving it. Maybe some expose would help? (yes I'm dumb and it's likely it just went right over my head). Or maybe it was a technical limitation and there was no more room for assets. Or maybe it was that 8 sprites per scanline limit ;)