First of all, here's a little treat. By now you've probably realised much of what Earthbound does parodies western societies and takes from popular American culture in some way. Well here's something you probably didn't expect. Remember the first time you walked into the cave of the past... In the future? It should have sounded like this:
Well, listen to the first few seconds of this:
And that's not where it ends. The next time you visit the Cave of the Past you get this:
Which you should recognise from the first couple seconds of this famous song!
As you can see, they take them and mix with them a heck of a lot, but I think they're brilliant references.
The other big one now!
Basically, half of like everyone in EB's world has different dialogue after you beat the game. While you're walking Paula around, or even just by yourself, go to a random bunch of places and start talking topeople and you'll really be able to understand one of the biggest messages behind this game (Ithink notable examples are the man in the business suit in Onett who says "you used to look a lot more helpless." and Mom's letter, where she is barely able to remember what you've been doing but the obvious point is she really cares about you, and has been noticing that, well, you're beginning to grow up now. These are the things that make Earthbound deep as well as strange, and you come to form a loving relationship with it. I keep finding new bits of dialogue every time I finish the game, there's a lot of people you can speak to, including your own team-mates (try showing Tony's letter to Jeff)! Places with sinister music suddenly have 'because I love you playing' OR, something you'll notice when you actually physically walk Paula home, the river area between saturn valley and threed is basically just ambience - a river flowing by, birds singing, it's pretty beautiful.
So yeah, explore the world post-game and see what you get, I think you'll really like it.