Monstrous Menagerie II: Hordes & Heroes has a launch date! Mark your calendars for November 12th, 2024. 300+ more monsters for your D&D 2024, or Level Up: Advanced 5th Edition games, plus new horde rules and rules for heroic monsters who level up alongside you--whether they be allies, companions, or foes! Click here to follow on Kickstarter!
These are the core rules. The game is not setting specific or genre specific. You shouldn't have any difficulty transferring characters and adventures over from D&D (any edition) or really most RPGs.