Finished the Fire Temple and the Spirit Tower and started doing some side quests.
Something I realised is that the side quests very quickly make the train experience better. The rewards always start with new tracks, which can make journeys and future side quests easier, but also new locations for treasure, new warp gates and bunnies. These in turn open up new side quests. The loop of request -> journey -> reward -> request is actually pretty addictive.
What boggles my mind is why this addictive gameplay loop is locked off until so late in the game (you don't get the cargo carriage until you've unlocked the Fire Temple - nearly at the endgame). Up until this point, every time I had to travel from point A to point B I kept wondering "I remember enjoying this, but it's actually really annoying. Was I just high on new Zelda hype?" Now that I've gotten to it, it's this part of the game that I remember. Traveling for side quests, rather than just wasting your time, actually gives you tangible, permanent rewards that open up the world and give you more options.
There's a missed opportunity here for a "city-building" aspect, for lack of a better word. By moving goods and people across the land, the game really should have shown the economies of each of the towns develop. This could have led to visible location changes, better prices in shops, greater variety of goods, new areas becoming available and upgrades for your weapons or train etc. As it is, these aspects are handled in other ways (mini games, Beedle and Linebeck to name a few), but it could have been as addictive as rebuilding Colony 6 in the original Xenoblade, building up New LA in Xenoblade Chronicles X or recruiting residents for Tarry Town if they'd had the notion.
Another Xenoblade gameplay design aspect they could easily have implemented if they were designing this game today would have been fast travel. For a game that's all about traversal, this seems counter-intuitive, but hear me out - you'd only be able to skip to locations you've found the stamp station for. Passenger / cargo transport, bunny hunting, exploration and warp gate unlocking would still require you to "ride the rails". It'd cut out a lot of the annoyance of revisiting older locations, preserve the side quest gameplay loop and make the stamp stations individually desirable (beyond unlocking Wind Waker Link's shield and the engineer's clothes). The fact that many of the stamp stations are inaccessible until you've revisited a location with new items means that the "main story" stripped of these side quests would remain largely unchanged. It might have allowed a greater variety of side quests too beyond the transport based ones.
My final gripe is that the train upgrades are largely cosmetic. Apart from getting an extra heart for all matching parts, there are no advantages to messing with this mechanic. It would have been nice for each train set to have a different stat boost, say top speed, smoothness, hit points, attack, shooting speed etc.
Anyway, still feeling like death, so I might get time tomorrow morning to do the Sand Temple. I probably won't get to finish the game before the deadline though. I need to sleep - doctor's orders.
EDIT: Finished the Sand Temple. That was a fun dungeon. Also tooted around finishing off various side quests - got the last of the stamps and all but one of the bunnies (which is locked behind a fairly long chain of side quests). The extra puzzle areas in each realm are consistently great though. Won't get to finish the game at this point as I really do need to sleep this afternoon, so I'd say I'm done.
All in all, there is a lot of fun to be had in this game, but it's all locked behind a central mechanic that just isn't fun enough to sustain a full game.
It could have done with some trimming or at least some way to skip inconsequential trips. The warp gates are placed to make side quests easier, but won't help you if you want to quickly duck into Aboda and visit Niko, for instance, or check if a new side quest is available in Goron village. It means the game wastes a lot of your time, which is a grievous sin, especially in a Zelda game. This makes it hard to come back to, however much I loved the ride toward the end.
Still, this game will always have a special place in my heart, since not only does it give the Hero of Winds, Tetra and her crew an enduring legacy, but it also lets you play as Zelda for the first time in series history. Her banter with Link is a highlight for me and gives Zelda the deepest characterisation of any Zelda to that point, on a par with Tetra.
The game lives on now as the Spirit Train level in Smash Bros Ultimate, featuring Engineer Link. Plus, Zelda uses a Phantom as one of her specials. Not only that, but it's main theme, Full Steam Ahead, is the track that plays in the background of the level. It's a lot more representation than Phantom Hourglass gets, for instance, and certainly more than Minish Cap.
With the way the game sold, I doubt very much that it'll ever get a direct sequel or a remake, which saddens me. Like a mastodon though, it'll always represent the end point of an evolutionary branch that never quite made it, whose time came and went and who has no place in the ongoing present.