It was a weird experience to see Sonic game on a Nintendo console... at least, it was back in the day, I guess. I always adored GBA for bringing "16bit" limitations into a much more modern development space, so we had a continuation of classic late 80s-90s traditions way into the 00s.

Generally - I loved the visuals of this game. While Gameboy had a much more limited resolution of 240x160, compared to even Genesis, its look and detail feel much more artistically refined, thanks to the experience and much more modern tools for developers available in 00s.

I add more than that - if you have an opportunity play it on a CRT! Via some S-video or other analog video cables to smooth pixels and tame colors, instead of GBA's built-in screen. It looks and feels stunning. All sprite detail, animations, little things like water and scaling effects - so many things which were practically impossible back in 16bit era.

I must add that Uekawa's late90s-early00s "modern" sonic works so well in 2d style. Upgraded stylistic visuals combined with the usage of his art style are just like made for each other much better than for 3d Sonic titles.

Music is nice but I must say obvious thing that GBA sound system is not good at all, so OST stuffers from it, esp "speed up" versions of themes.