Shortcut to beating the game:
Step 1 : Buy your upgrade
Step 2: Exit Shop
Step 3: Refresh the Browser (F5 or CTRL-R)
Doing so with allow you to keep your upgrade and your money.
The idea sounds good. I´ll putt this on the list. I plan to make upgrades for stations and the world/scene in general. However, there will be a separate currency for those. But there are still many things I want to implement before.
Rigth now you get more passengers from wagon upgrades. I did not explain that in the game but you get more passengers in average if you upgrade the passenger wagons. Every time you visit a station you get a random amount of passengers between 1+Wagonlevel -> max passengers.
I guess it´s time to work on those information windows.
 "Plinko Idle"){kind=icon}
 "Otter Life"){kind=icon}
 "Idle Drone Delivery"){kind=icon}
 "Synergism"){kind=icon}
 "Absorber"){kind=icon}
 "Incremental Adventures"){kind=icon}
 "Quepland"){kind=icon}
 "Idle Breakout"){kind=icon}
 "Idle Machine Learning"){kind=icon}
 "NGU IDLE"){kind=icon}
 "Idle Facts"){kind=tracking}
 "Steam Engine Clicker"){kind=icon}
 "Crystal Adventure"){kind=icon}
 "Reverse Idle"){kind=icon}
 "Idle Train 2"){kind=icon}
Please send me a screenshot of your game: click on the "Game bug" link near game title.