The game is frustrating me right now. Game over-ed to the bosses of Zone 7 and then twice in Zone 9. Neither boss is very good at all and both involve tons of waiting around. Being sent back to the very start of the zone is not a lot of fun, not something I remember fondly from childhood.
Also, Zone 7 was weak. I honestly could barely tell I wasn't playing the original zone. In most cases they've done a great job of remixing old zones but here it literally just felt like the exact same thing. At least the very next zone was absolutely fantastic.
I really should get back to it and beat it, but the thought of playing through the entirety of Zone 9 for a third time in a row just to have to fight that awful boss again is wearying. It's the worst kind of boss - challenging while being incredibly slow and boring.
I got my first emerald on fifth level. So the objective to finding an emerald is to explore and find a giant ring?
What are the medals for?
Sorry, been gaming since 84 but Sonic has never been my thing and still learning.
You want to explore, find giant rings and get 7 emeralds before beating the game, though most won't do that on their first playthrough. In other Sonic games this sometimes unlocked a 'true' final level or boss.
As for the medals they unlock things like a sound test and other minor features in the menu, I believe. They aren't critical to the actual game at all.