True, Mephiles wasn't a part of the story like say, Erazor Djinn, but note that a lot of crossover titles aren't considered main Sonic canon. Mario & Sonic. Sonic & Sega All Star Racers. I think being that Runners had Mephiles as a playable character and crossed over with Puyo Puyo that it might lump it in together with that as a cameo title. Along with being a discontinued title as well too, yes. I also wonder if Speed Battle is lumped under the crossover line too with the movie tie-ins. Certainly could use some room for clarification. I also hardly doubt any of the old Java or Sonic Cafe games are canon due to both obscurity and lack of availability.