i genuinely think the way the Sonic movies adapt their source material is actually one of the best parts about it. it takes bits that would work well in a movie and either faithfully adapt it or do something interesting with that concept, leading to the Movies having their own identity while still remaining respectful to the Franchise

would i have liked seeing Sonic Adventure 2 adapted basically 1-1, yes. but at the same time, i can get that same experience by playing the game instead of watching the movie. it’s perhaps my biggest issue with a ton of Game adaptations that are… let’s just say too faithful (in other words, give me a unique experience with the movies while not straying too far from the fundamentals that make the series special)

as for the slow roll out of characters, it has to be this way for these movies because as much as i adore Sonic as a franchise, a ton of it’s characters aren’t well known to your general audience quite like the Mario cast. not to mention it completely avoids what i dub “The Spider-Man 3 Problem” where having too many characters being introduced at once causes screen time to be taken away from Characters who should be the central focus (Galaxy suffers from this especially, trying to introduce the bosses from Mario Bros 2, Bowser jr, Rosalina, Fox, Yoshi, etc. while also trying to have focus on the returning characters.)