I count myself as a fan of trains, insomuch as I think they're the best way to travel around.
But there's a dedicated section of people who take train fandom to a whole other level.
They're obsessed by the history of rail travel, the smell of burning coal, and the esoteric model names and associated paraphernalia.
Trainz Simulator 2 is for such people, and nobody else.
This hardcore focus isn't remotely surprising for those who have been paying attention. The Trainz series has been seeing to the specific wants of train fanatics since 2001.
As the name suggests, this is the second Trainz Simulator game to hit iOS, and it's essentially a refined and expanded version of the original.
You get the same dauntingly vast virtual train sets to play with, plus extra routes, improved graphics, streamlined controls, and even a multiplayer mode.
There's a surprisingly intuitive series of tutorial missions that ease you in to proceedings at a glacial pace. Taken together, they're longer than most full iOS games, but at least they're comprehensive.
You'll learn how to monitor and adjust your train's speed, read signals, and couple and decouple carriages in a train yard.
When you're done, you're ready for the free roaming and mission modes that make up the game proper. And that's where train and simulation fans could well lose tens upon tens of hours.
The main game is an austere experience, filled with functional menus that appear to have been taken directly from the '90s.
Everything chugs along in a basic graphics engine that doesn't seem to be much newer.
Of course, with a series of sprawling maps containing miles and miles of tracks, junction points, AI trains and the like, it's easy to see why Trainz Simulator 2 might not be the best-looking game around. It's truly vast.
Keep pinching out from your train, and the world will soon resemble a schematic, your trundling locomotive reduced to a speck.
At times like this, the graphics engine, despite all its bland pop-in textures and stuttering frame rates, is almost impressive.
You can choose to go with casual controls or the full hands-on expert system. Needless to say, the kind of people who will be interested in the game will only want to use the former to begin with.
The touch controls work reasonably well, but the casual speed slider is still a little too sensitive for its own good, making it easy to break the speed limit, which is a train-driving cardinal sin.
Train set for life
But Trainz Simulator 2 isn't about slick controls, smooth frame rates, or tight gameplay. It's almost not a game at all.
It's a tool that lets you build your own railway line from scratch. As long as you have the patience and inclination to do so.
If that's you, you can download the game safe in the knowledge that there's a ridiculous amount to sink your teeth into.
If it's not, Trainz Simulator 2 is one to avoid.