Tails of Iron.
For a vast majority of the game, the soundtrack is diegetic. If you hear music playing, there's likely an on-screen source for the music. In a bunch of boss-fights, you'll see a couple dudes in the background playing music and they'll only start when the battle kicks off(and immediately scamper off the moment the boss fight is over).It even applies to some bits later in the game when someone has a boom box playing music(which gets louder and softer depending on how close that boom box is to you).
I also liked that there's a notable amount of change in some of the locations. Early on an army of murder frogs swings through the kingdom and basically tears up the joint and you spend like the the beginning third kicking the frogs out of the castle, the countryside, a town and a ranger camp, as well as some underground areas. And as you progress through them killing the froggy boys, the areas are often wrecked and torn up and on fire, with certain entrances and doorways blocked off. After the locations are cleared and you return to them later, you seem them getting repaired and repopulated as the rats who fled the area slowly reclaim the area and by the ending part of the game, these areas are either peaceful and mostly repaired(the countryside) or bustling and rebuilt(the town, the castle and the ranger camp). It's a nice transition and feels like your efforts to clean up the area are having a tangible effect on the world and you're making it a better place. You don't seem to see it very much in games that I've noticed.