OpenTTD

I became a master of engineering in the field of transportation, thanks to having played TTD back when I was merely a kid. Having spent thousand of hours here, I can't help but say this is among the most addictive stuff out there, albeit one that lets you actually spread your creative wings. Go for it.

OpenTTD is a really good and mature game -- in being a transport simulation. The graphics are old-fashioned, there is no real end of game, and controls are utterly unintuitive (at least with my Linux / Unix version): You need to hold the mouse key to open a context menu, and it took me ages to find out about how to colour different vehicles (the colour was visible, but it would have never occurred me where to click in order to apply a change). Then, there is the problem that renewing your vehicles is highly burdensome and often requires a lot of manual effort (it's easier when switching train types, e.g.). But what I find most annoying is the inherent AI of transport: Passengers do not seem to go from one place on the map to the other, but only to the next station, whichever that is. Goods do not have to be transported to one specific place, which would allow for building a network, but they only need to find some demand anywhere. This said, the game is pretty awesome. I consider it best to play train-only, maybe (only maybe) use road transport as well. Never use planes, they will spoil the challenges inherent in map design and economy. The standard route to riches is easy: Go for coal and connect several mines to a power plant each (it ought to be more mines than power plants, for plants are only drop-off). Keep in mind that distance has the major impact on profits. So the more supply and demand are topographically apart, the sooner you grow rich. Counter-intuitively, do NOT go for the shortest route, but for the longest you can afford. Between loading and unloading, that is. After unloading, direct your trains to a loading point nearby (a coal mine, e.g.) and have them go back to an unloading point in the vicinity of the original loading point. That makes it: A (load, mine) >[far]> B (unload, plant) >[close]> C (load, mine) >[far]> D (unload, plant) >[close]> A. Oh, and group your vehicles. Good old game with outdated mechanics and a rough edge -- but fun.

This is an all time classic. Buy it, mod it, play it, love it.

It takes quite a while to learn the mechanics of this game, at least to the point where I felt proficient at the game. There are lots of little things that aren't clear which require some hunting around on the internet for tips, but once you get them the game really opens up! I already have over 500 hours in this because I keep coming back to it for more. The original developer of the game, Chris Sawyer, really outdid himself when he created this game, along with other known titles like Rollercoaster Tycoon (can be found here on GOG, but OpenRCT2 also exists (requires game files tho)), all programmed in Assembly which meant that it ran lightning fast when it originally released.

People took one of the greatest old games ever, completely rebuilt it from scratch on a modern engine, extended it with TONS of great stuff, keep it active for over a decade with updates, improvements etc and all this for FREE. Where is the sixth star option, GOG?