lol nps. Well this train is about a third of its original size. Didn't realise I had a max of 102 GAs I could create. So depends on if you're factoring in the original plan or not.

Including the original plan, designing layout of a city by making the rail network map then trying to incorporate game names / game objectives / story or a reference in one way or another into every segment. That's what took the longest.
I.E Not having a transition into outer space without creating a design incorporating a the reader getting into a rocket / space craft (Yeah I did it in one of the prototype designs, but failed at getting back down to earth so removed it) Hence games like Homeworld being referenced just as "Home"

So theoretically, on and off I was playing with the design for, only including the segments used, about a week or so. Don't get me wrong, that still going about my normal life with work, kids etc.
Then listing it was a bitch, I screwed up with the time I wanted it to finish. I wanted it to finish, not this Monday, next Monday. So I was going to have a few days to list it, link it all up, test it, then add some additional shit. A few keys I had expired or I can't find them, so games got swapped out etc.

Listing it all took me about 7 hours total. Spent 3 hours or so before going to bed. Then woke up and realised I screwed up the timing, so instead of deleting the GAs, I listed the rest and linked most of it on my phone to, from and at work or while I'm at home outside having a smoke or whatever.

So, realistically, long story short TLDR: About 2 weeks for everything you see here, add another 3 weeks for the original plan. See below image for the original. Still missing some things but yeah.

View attached image.