Rail Master Tycoon: Idle Train

I have a problem in the coal map of a completely impossible task. It asks you to upgrade the passenger line to level 175, but once you've done 150 levels, the line just says max and you can't upgrade it any more. Otherwise I'm finding the game quite addictive. Relatively simple, but enough to do to stop me getting bored

No forced ads, only reward ads, got to appreciate that! The game is otherwise a fun little game as you build up and watch your rail network go about it's business. 1 star off 5 simply due to the farming and fishery not getting much attention in upgrades. Need to add automation and harvest improvements for those facilities please?

A star is lost due to its severe limitations. This is a terrific and unique game, limited only by its eras. Forget that I've been patiently awaiting the 2000 level, which is allegedly "coming soon". This could be a game with a dozen or more levels. ...and I wish it were. I've played the same 6 levels repeatedly, and it's gotten pretty redundant. ...There simply must be a way to keep it fresh longer.