Things I liked:
I actually think the graphics of Earthbound have aged very well. They're simple, but the style is clean, Peanuts-like (which I'm sure was deliberate), and uncluttered by excessive texture patterns.
I also think that Starman and Diamond Dog are David Bowie references.
The soundtrack was good. It was less anthemic and sing-songy than Mother, but more moody and better at creating tension and uneasiness.
Room for improvement:
There's no run button in the game and once you get a Teddy Bear or another party member, you can't ride the bicycle any more. This is cruel to the gamer. Skip sandwiches it is, I guess.
Item inventory management was a bit bizarre, though it fit the tone of the game well. Most modern RPGs seperate items into different categories: quest item, healing, equiped, etc. while Earthbound placed them all in one list, per person. I mean, I guess someone has to carry the map and it does take up space, but that also means I can carry one less Hamburger. Convincing, but not what we're used to as gamers.
Oh, and the way items are stored is a bit of a pain. Calling Escargo Express was cool, but it wasn't very flexible. What if I wanted to do a delivery and a pick-up at the same time? You can't just swap items in and out of storage without going through the motions twice.
Another thing I don't like about the game is that without the official strategy guide, you miss out on a lot of the aesthetics of the character design that we see in the clay models. If Earthbound ever got remade, I'd love to see the clay figures incorporated into the game's art. There's just something about seeing those that makes me look at the game and it's inhabitants differently.
I also feel like the Western version of the game suffers for using the EarthBound name instead of MOTHER. They're both cool names, but the graphic design and box art used with the Mother logo were much more intriguing and provcative and might've lured in more Western gamers.
