It's hard to say much about Golden Sun, since it's a pretty traditional old-school RPG. Like many of the genre, it features a turn-based battle system, it's set in a medieval-ish land, it features characters with the ability to use magic and summon powerful monsters, etcetera... Its most unique mechanic is the ability to use spells on the overworld to solve puzzles and interact with NPCs (which is a lot of fun actually).

Overall, it's a fun but not particularly mindblowing game. Mostly recommended if you're looking for new RPGs to play.