This is a great game, if you like automation, solving logistical problems, eg: problems with mass supply of resources, problems with power, etc. Or, if you like Trains.
The game has a very robust Train System within it, which is entirely optional, in that it is not required in any way to complete the game. It is, however, extremely satisfying and fun for me, as someone who like the Idea of model trains as a child, but could never really get into them seriously because of space reasons, how annoying and fiddly a really complex setup was to make, and because it all felt somewhat pointless. As in, you could speed your trains around, but to no real end, or purpose.
Factorio fixes these things, firstly by having some very nice features for smooth building of tracks and whatnot, features to help automate train movement, and most importantly, by giving your trains purpose! These are not passenger trains, or tourist trains. These are Goods Trains, designed to carry vast amounts of cargo, over middle-long, or Very Long distances, extremely fast. Trains, managed well, are far and away The Best method at your disposal of transporting goods around your factory, no other method comes close at any distance beyond one or two screen widths. (Besides a certain exploit but never mind that.)
If you like the logistical challenges the basic game offers you, you will love trains as well, since the problems and challenges associated with loading and unloading cargo from trains, as well as the designing of a Rail network capable of handling multiple trains - no upper limit there friends :) - are some of the most complex and challenging parts of the game.
The basic game itself, is also excellent, especially during the early-mid game where things are relatively small, and the hassles of the slightly clunky building controls are not as noticeable. My recommendation is to absolutely invest into Construction Robotics as soon as you possibly can, as the mid-late game will become really unpleasant if you are still manually placing all your components. This is, incidentally, the only real complain I have with the game, as the primary activity is placing and rotating entities to assemble your factory, but the actual controls and mechanisms for doing so are pretty clunky. Tolerable at a small scale, but construction robots and blueprints are the only way I can play the late game.
Having said all this, the game is about as feature complete, and polished, at this point, as any so called finished game (ie: not choosing to label itself Early Access). So, anyone who wants to, feel free to give it a go now, it is certainly more feature complete than Anthem (Anthem currently, btw, not even at launch). I recommend buying it on GOG by the way, as they have some excellent and convenient rollback features, that essentially can be used to play the game at any patch version you choose, which I really like.
