I think I'm getting close to the end of Earthbound. Got the 6th sound(Pink cloud) near Dalaam, all that's left is to get on the Boat from Summers and begin the LONG trek to the 7th and 8th sanctuaries. At first I was like, I got this. It's the old school game structure where you have a linear series of towns, each of which you need to solve their local problem before you can pass through whatever barrier is keeping you from progressing to the next one(Roadblocks, tunnel ghosts, etc), which normally ends when you get the global airship. Earthbound, keeps this particular pattern until you reach fourside, the local big city, which has only one road in and out and that's the one you arrived on. After this you end up doing a bunch of weird backtracking and sidequesting to get a couple more sanctuaries, go to summers via winters(it makes slightly more sense then it sounds) before eventually the game goes back to being linear again for the last stretch. And there's no global airship, the closest thing is a UFO which takes you all of 3 places and breaks twice, though you do get two teleport spells which all you to visit places you've already visited, which makes backtracking a lot easier at least.
Also, I don't think I knew about Jeff's tool use/repair ability the last time I played it. Basically as you go through the game, you can/will pick up "broken" items and when you sleep at a hotel, there's a chance Jeff will fix one of the items overnight. Some of these items are meh consumables, but some of them are useful tools and weapons, like a device that sucks HP from your foes and heals Jeff(making him a tech vampire) or drops an enemies shield(not super useful because most enemies don't have them) or is a fucking bazooka. These tools can make a difference if used properly(though each one takes up a valuable inventory spot) and Jeff needs to have high enough IQ to fix the tool in the first place, so it's basically something you either grind for or don't get the really good stuff till late in the game.