- B-Team Sequel: This is the only game in the series not to be published and developed by Sony (who co-owns the franchise alongside Production IG) and Japan Studio.
- Christmas Rushed: Suda and his team at Grasshopper had exactly five months to push this game out of the door while the anime was still airing in Japan. The development team had to reuse the same engine and assets from Killer7 while Suda and the writers had to watch the anime to get some context for the game's story. Despite one major setback, the game came out just one month before the anime's conclusion with no issues.
- Colbert Bump: The game remained unknown for years, with the only people aware of its existence being fans of the show and Grasshopper's fans. It wasn't until many years later when Youtube content creators like Hikikomori Media and TheGamingBritShow talked about the game on their respective channels, raising some interest on it, which finally resulted in fans trying to translate the game.
- Development Gag: The Moonlight Syndrome 2 posters scattered around town aren't just a reference to that game, but also a nod to the game's Working Title.
- No Export for You: The game was never released outside of Japan, even during its runtime on [adult swim]. What makes it even stranger is that Bandai Namco was still releasing games for the Playstation 2, including other anime licensed games.
- What Could Have Been:
- Early screenshots of the game shows actual blood coming out of enemies during combat, but they ended up being replaced with sparks on the final game, possibly to keep the game's age rating to B, CERO's equivalent of ESRB's T rating in Japan.
- According to Suda51 in the "The Art of Grasshopper Manufacture" artbook, the game was originally going to end with Saya dying, only for the game to reveal that she's a Chiropteran clone of the original. However, this ending was scrapped after the negative reaction from one of the executives in charge of the game.
"There were points when the person in charge got angry at us. In our scenario protocol, Saya dies. But that's actually a clone. When I wrote it so that Kaname and Saya are Chiropterans, he got extremely angry and said, 'You can't kill the heroine!' Even though I told him, 'It's just a fake,' he still shot it down. He really got mad. Yeah, that's how it was. Leaving the game as it was in the original work wasn't an option; somehow, killing the heroine wasn't interesting. Well, they got mad."
- Working Title: Moonlight Syndrome 2.
