There is plenty of freedom and many places to revisit and have fun in.
You're just intimidated by the overworld being so big so you refuse to do it.
Quoted for truth :)
yeah, you don't neccesarily need to go right on to the next quest, but the games story makes it seem so urgent, that you almost absolutely HAVE to.
That being said, I probably spent 4 hours of gameplay alone on the chicken flying minigame :/