Wherever inspiration for a bit of "I need to scratch this itch" come from, personally I am the same and I love it.
EDIT : Also, Factorio is top.
I'm trying to beat out the "not productive = waste of time" mentality out of myself, and I'm getting much better about it! But Factorio somehow always brings it out of me :P
A reminder to spend a goodly amount of your time on this Earth just basking in its pleasures, large and small, "productive" or otherwise.
Of course creativity's also a subject I pressure and criticize myself about, whereas with a game you may not hold yourself to those expectations.
I love Factorio though, it's much more about building and strategy than optimization and puzzle-solving. You can do the latter if you want to, or you can just play with trains.
It’s this type of challenge that keeps things fun for me, but at the same time, feels a lot like the problems I’m solving at work.
https://wiki.openttdcoop.org/Line_hierarchy
https://wiki.openttdcoop.org/Backbone_Hub
If you prefer a video: https://www.youtube.com/watch?v=-YfxugbgQqs
This is why I like Simutrans: the passengers want to go from A to B.
OpenTTD towns perpetually grow as long as you service them. Which means that every passenger station will have infinite lines (as towns grow, more-and-more passengers will need to be serviced across all your stops).
This means that OpenTTD is designed to automatically make passenger traffic "harder", there's always more passengers to carry. The limit is purely the design of your railway. You might have to put the game on fast-forward for 30-ingame-simulated-years before the towns grow to that size, but it always happens.
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Industry in the game also grows bigger, but related to service station %. Early trains cannot service any industry quickly enough to consistently make industrial growth, but later trains with higher speeds will leads to more station% bonuses, making the late game also fill up with coal, lumber, steel, and other materials.
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There's no challenge on the money side. Just place 2 airports on the biggest towns across the map and you'll never run out of money. (Distance x speed traveled leads to profits, and airplanes are fastest and travel the furthest without any rail-costs, making this an appropriate strategy even early in the game)
The "real" challenge is: how many passengers can your rail-junction support? Can you max out an airport?
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My issue with OpenTTD is that the game sometimes wants to pretend its 1x1km blocks, but other times that doesn't make sense at all. Ex: Bus stations are 1x1, and there's no way my bus stops around town are 1km wide.
I think the main thing OpenTTD needs is a "rebalance". Maybe the grid needs to be 10x10 meters (10,000x more detailed) than currently.
I think this 1km x 1km limitation was because computers in the 90s were not good enough for a more detailed simulation. But we have the weird ship-behavior (because ships don't collide with each other), and other such issues partially due to this weird size incoherence in the game.
It turned it from "just build a city/logistics framework" to "build a city that meets these requirements, and then move to a map with harder logistical challenges".
It really helped me get into the city building and logistics genre rather than just dumping you into a pure sandbox, and the only recent games I can think of that had proper campaigns were Frostpunk (sort of) and Nebuchadnezzar (which has... other issues)