for me it's the other way around. i do like Adventure but it's a game full of compromises, with most areas needing to work for multiple characters and the Adventure fields ultimately limiting the scope of the game to three relativey-close locales. then comes Sonic Adventure 2, a game with purpose-built stages for each playstyle spanning multiple continents and even space. while the treasure hunt stages were arguably worse, the mech stages were ten times better without the timer and the random tranaformations. and the speed stages, oh man. without the spam dash you really have to learn how the physics and movement options work, but when you do you're tearing through the stages rolling on walls and making gravity-defying leaps. it's amazing. 3D Sonic does have a trend of turning things that were challenges in 2D loops into just breather setpieces, but SA2's introduction of rails is the one time they bucked that trend- get enough momentum going before you hop on or you're not going anywhere! shame every game since has locked your speed once you're on them. the extra power-ups and chao boxes scattered throughout the levels give you extra places to explore and reason to do so. to me Sonic Adventure 2 really finally delivers on everything Sonic Adventure wanted to be. it does lose points for it's rocky voice acting and overreliance on automation- although in both cases to a degree less than Adventure 1- but it's a great game and the only 3D Sonic i can say that about, as close as Adventure 1 and Frontiers may have came