Train Sim World

This is going to be a very cautious but none the less enthusiastic recommend from me. I bought the 2020 edition because of course I did, and the first thing I can safely say is that this is, by and far, the *most* interactive train sim money can buy. And people complain about shorter routes, very much so, and that's a valid complaint: but *if* you take this to be the tradeoff for a complex system simulation then it's really, truly worth the money.
Out of all three of the routes on offer here, the LIRR is by far the most buggy and unpolished, but I expect we'll get the fixes for it when we get the fixes for the NEC (in fact, ATC isn't even toggleable in the cab presumably because it's being reworked) - *if* we ever get it. GWR is short, sure, but it's a good route IF we get the Passenger Information System implemented. CSX Heavy Haul is a good route IF they fix the EOTD bugs which the game has had since release. This is something I want to touch on just briefly because everyone else had already mentioned DTG's frankly awful business model, and I am by no means a fangirl - but I can recognise something with potential when I play it.
The *if* continues elsewhere, however. This is a game for the patient, like someone else said - for the patient and for those who love technology designed to go at speed even when it's standing perfectly still. If you're at all like me, and you like to spend your evenings with a hot mug of tea in passenger mode, watching the rain and being comfy, then this is also the sim for you. If you're like me, and you like absurd levels of functionality with ultimately no purpose, then this is the sim for you. If you just like to plug a loco into a route, kick it on, not give a ♥♥♥♥, and enjoy the wonder and majesty of trains as they are, without a trillion sub-systems to flick on and off and demister switches to twiddle like errant nipples, then do yourself a favour and pass on this in favour of Train Simulator or some other simulation platform.
For the sake of clarification, when I say "complex systems simulation", this is what I mean: there's a scenario on CSX called "Clear Cut" and it involves moving anywhere between one and three locos to where they need to go. I spent two and a half hours walking from one loco to the other, and if I was moving the forward locomotive, I'd switch off the back, play with the settings, adjust the headlight switch from trail to hood, and do all kinds of fun things - and the game kept giving me points for it! The entire thing made the actual driving feel like a moment where you can sit down, look around, and go "Right, that's everything sorted for the journey ahead, then." You'll know what every valve does and how it works, and when something goes wrong (something I actually enjoy in this game despite it being bugs about 50% of the time), you're stuck sitting there with a manual, rifling through switches like a magnificent Rube Goldberg machine. And you can do this in Service Mode with a timetable open on your phone/screen/kindle/microwave until your family comes to check on you to see if you're still alive. It's tremendous. The only other sim I've experienced this in is DCS and I have to say, for me to be able to compare a game to a literal military study sim is pretty dang impressive, especially given the price!
If any of the above tickles your gender-non-specific groinal regions, then check your PC specs and buy it if you can run it. Do yourself a favour, and buy it. My apologies for the meandering review and I hope this helps!

Before I go into detail, this game is only for a certain demographic. There is no modding, editing, or world building. This game is caters mostly to those who have a somewhat through understanding of rail operations and locomotive operation. With that being said, if you aren't familiar with the controls, the game has a pretty good tutorial interface and don't feel intimidated by the game.
I bought this game back when it was just CSX heavy haul, and let me tell you, this game has come a long way. The game mechenics are very smooth and well done (With the exception of a few bugs here and there). The models are very high quality and very accurate (at least with my experience). I personally play on beefed up rigs, and for the most part I have a consistent frame rate, however I do face frame drops in certain high populated places like big towns or yards with lots of trains.
What sold me on this game compared to other train simulators are the ability to freely walk and move about the train. That part is a BIG for me and its something I've been waiting for in a train simulator for ages. The ability to either choose to drive, ride, or spot trains gives me more freedom to do as I please within the world.
On the other hand, there are some tradeoffs that I need to adress. I feel that some of the sound design has been neglected on the American trains, especially the horns. The only american horn that has a decently accurate sounding horn to the real thing is the Peninsula corridor's Caltrain (and even that sounds a little off). I also feel like some of the horns aren't loud enough (at least for CSX). Another trade off of this game is the content to price ratio. This game will QUICKLY burn a hole in your pocket if you don't wait for sales. For the steep price, of a route, you only get a couple locomotive, and a small handful of rolling stock types (for example the peninsula corridor only comes with 2 locomotive types and 3 railcar types). I feel as if the add on locomotives should come as free updates to the route instead of DLCs that cost half the base route
just to put it into simple terms
Pros:
great graphics
sharp locomotive/rolling stock modeling
great interactivity with the equippment
Well done interface
freedom to drive or spot trains
great driving and camera mechanics
very realistic train operations and handling
good tutorial system
Cons:
Steep price
lack of content
lack of good horn sound design
some bugs
addon locomotives cost money
frame rate sometimes is inconsistent
So in conclusion, I personally would recommend this game to somebody who has a good understanding of trains and has already invested a bit into gaming. I personally love playing this game and will continue to play it. I personally think the Pros outweigh the Cons, but that is up to your judgement. I hope you found this useful.

It's a great game. but i would like more regions to drive in like Australia.

Only buy it on sale. It's a good game but not worth the full price. (not even counting DLC)

it is very realistic. i work for the railroad as an engineer and this game simulates my job at 99%

Ultimate strolling along the rails trainspotting walking sim.

This game is, unfortunately, a massive missed opportunity. The graphics are lovely, the driving experience is solid, but the world simply feels empty. I understand that it would be an absolute processor killer to run a full realistic timetable, but when you can see from one end of Paddington to the other and not a single platformed train, it leaves you feeling as empty as the world. The ideas here are wonderful, although the DLC is varied and expensive. Sometimes I even leave it running on passenger mode while I'm writing so it feels like I'm writing on a train.
I do reccomend this, with that key proviso that it is just a little lacking, and sterile. What this game is crying out for is the ability to modify the timetable, or a slider to help choose how well populated the line is, for those of us with high end machines...