For a handheld game from the early '90s, this game holds up rather well. The platforming is pretty good, the screen is big enough to usually see where you're going. While not quite as charming or action-packed as its 16-bit counterparts, this game serves its purpose.
There are a few places where it is lacking, however. Namely in the boss battles and the chaos emeralds. The boss battles are generally really easy, and not as creative as I'd expect from this series. The chaos emeralds aren't as hard to collect as they'd become in later handheld Sonic games (looking at you, Sonic 2), but most of them I never would've found without a guide. They aren't even challenging to get; just in weird spots that don't feel satisfying to me (outside the first, that one was pretty good).
And, despite the game being good for what it is, it's still hurt by that same thing - it's only as good as a handheld platformer from its era can be. I still wouldn't recommend this to anyone who isn't a big Classic Sonic fan. Three stars for going above and beyond most of its brethren, but stopping there because the game still isn't anything fantastic.