I hate it when developers make what they say are side games in a series essential to canon, especially when they don’t tell you they’re doing it or when they go into the side game not planning to make it canon and then decide it’s canon during or after development.

Or I should say, I hate it when developers make the next main series game assuming you’ve played the essential “side” game and leave out or half-ass their catch-up for people who haven’t played it. I call it “Chain of Memories syndrome” after when Kingdom Hearts made Chain of Memories essential to fully understanding KH2.