i think i understand the magic of sonic adventure 1 now, it was their first attempt at making a 3d sonic (properly) and so it's not completely all just corridors where you go super fast interrupted with awkward platforming sections, when you go fast there's still stuff you need to do to avoid-
-obstacles, and the platforming is still pretty fast paced and stuff. also there's still obstacles in like sonic generations, but it's not a simple "click L to avoid!" like a QTE, you control it yourself. there's a lot of platforming that was incredibly clunky but i think if it was made-
also just the levels being more than corridors, actually being filled out other than the place you're supposed to go. an area having a lot more explorability (like i found out shit about red mountain & big's hot shelter that I NEVER knew existed), it's just peak.
