Factorio is a top-down RTS industrial base-building game, focused on automation and modularization. You are dropped into a foreign world with almost nothing and must build increasingly complex arrays of machines to assemble all of your needs, from defenses to railroads to the rocket that wins the game.

The core mechanic of the game is simple:
1. Pull an item out of the machine which made it, using an "inserter" machine.
2. Use conveyor belts and trains to move the item to another machine.
3. Consume the item in the latter machine to make a more complex item.
4. Repeat.
This process gets repeated over and over with increasing complexity such that a facility can ultimately look like a sprawling labyrinth of tightly-woven belts and inserters, or a neatly laid out motherboard-esque array of lines and processors, depending on your play style.
It's a game of scale: build a small plant that makes just enough steel to feed your munitions depot, or make a massive complex that can churn out millions of batteries per hour to satisfy all of your needs - and ship them all across the map by train. The game is totally open-ended, so you choose how to approach your problems.

This game has some elements of combat, though they are not at all the focus of the game. Instead they provide a diversion from the mammoth industrial goals set before you, and a sense of urgency in the need to defend the machines the you've worked so hard to cultivate.
The combat features can be entirely disabled, providing a semi-sandbox totally relaxed play experience - though given enough time and research you can build defenses strong enough to have essentially the same effect.

A single game will last at least ten hours (there is an achievement for winning in under eight, which is insane (but possible)). The game lends itself well, though, to watching a show or listening to a podcast while playing. You can expect steady activity interspersed with brief periods of waiting for your machines to accomplish some task.

Factorio is one of a small elite of games that are equally fun in single- and multiplayer. Adding to this, any save can become single- or multiplayer at your discretion. If you've put 30 hours into your megafactory and want to bring in your friend who is good at setting up nuclear power, no problem. If your friend has been hosting a massive rail-laced world for weeks and suddenly takes a year-long sabbatical in the Himalayas, you can load up your own copy and continue to play.

Factorio is still in active development - and has earned the adjective "active" more thoroughly than any other game I've played. The developers publish updates at least once a week, patch bugs extremely rapidly, and are still steadily adding new content.
The coolest feature of this game's development is the Friday Factorio Facts, a weekly blog by the game's creators discussing in detail some of the problems, ideas, innovations, or solutions facing them at the time. For a game about innovation and fine-tuned machinery, this only adds to the appeal. These updates were on hiatus for a while after the 1.0 release while they were in the very-very-early stages of 2.0 development, but those have since been resumed.

Factorio has rich and active modding community. If a player has exhausted their interest in the game in its original state or wants something a bit more challenging, many mods exist to give the game a whole new flavor. Additionally, the community maintains an array of quality-of-life mods to fine-tune the game to their own tastes, though for this particular game the developers have consistently paid close attention to quality-of-life features.

Factorio is appropriate for all age groups. Even the combat is non-gorey, appropriate for budding gamers.
This game is also accessible to any level of gaming experience. Veteran gamers can take things to the grandest scale their hearts desire, while newbies can take things slow and dip their toes into analytical, constructive gameplay.

Because each run occurs in an infinite, randomly generated world and gameplay is totally open-ended, Factorio has enormous replay value. This is a game that is very easy to put down or pick up at a moment's notice, so long or short sessions are both comfortable ways to play.

Factorio is worth many times its price and is a fine addition to your library.

Factorio is a top-down RTS industrial base-building game, focused on automation and modularization. You are dropped into a foreign world with almost nothing and must build increasingly complex arrays of machines to assemble all of your needs, from defenses to railroads to the rocket that wins the game. The core mechanic of the game is simple: 1. Pull an item out of the machine which made it, using an "inserter" machine. 2. Use conveyor belts and trains to move the item to another machine. 3. Consume the item in the latter machine to make a more complex item. 4. Repeat. This process gets repeated over and over with increasing complexity such that a facility can ultimately look like a sprawling labyrinth of tightly-woven belts and inserters, or a neatly laid out motherboard-esque array of lines and processors, depending on your play style. It's a game of scale: build a small plant that makes just enough steel to feed your munitions depot, or make a massive complex that can churn out millions of batteries per hour to satisfy all of your needs - and ship them all across the map by train. The game is totally open-ended, so you choose how to approach your problems. This game has some elements of combat, though they are not at all the focus of the game. Instead they provide a diversion from the mammoth industrial goals set before you, and a sense of urgency in the need to defend the machines the you've worked so hard to cultivate. The combat features can be entirely disabled, providing a semi-sandbox totally relaxed play experience - though given enough time and research you can build defenses strong enough to have essentially the same effect. A single game will last at least ten hours (there is an achievement for winning in under eight, which is insane (but possible)). The game lends itself well, though, to watching a show or listening to a podcast while playing. You can expect steady activity interspersed with brief periods of waiting for your machines to accomplish some task. Factorio is one of a small elite of games that are equally fun in single- and multiplayer. Adding to this, any save can become single- or multiplayer at your discretion. If you've put 30 hours into your megafactory and want to bring in your friend who is good at setting up nuclear power, no problem. If your friend has been hosting a massive rail-laced world for weeks and suddenly takes a year-long sabbatical in the Himalayas, you can load up your own copy and continue to play. Factorio is still in active development - and has earned the adjective "active" more thoroughly than any other game I've played. The developers publish updates at least once a week, patch bugs extremely rapidly, and are still steadily adding new content. The coolest feature of this game's development is the Friday Factorio Facts, a weekly blog by the game's creators discussing in detail some of the problems, ideas, innovations, or solutions facing them at the time. For a game about innovation and fine-tuned machinery, this only adds to the appeal. These updates were on hiatus for a while after the 1.0 release while they were in the very-very-early stages of 2.0 development, but those have since been resumed. Factorio has rich and active modding community. If a player has exhausted their interest in the game in its original state or wants something a bit more challenging, many mods exist to give the game a whole new flavor. Additionally, the community maintains an array of quality-of-life mods to fine-tune the game to their own tastes, though for this particular game the developers have consistently paid close attention to quality-of-life features. Factorio is appropriate for all age groups. Even the combat is non-gorey, appropriate for budding gamers. This game is also accessible to any level of gaming experience. Veteran gamers can take things to the grandest scale their hearts desire, while newbies can take things slow and dip their toes into analytical, constructive gameplay. Because each run occurs in an infinite, randomly generated world and gameplay is totally open-ended, Factorio has enormous replay value. This is a game that is very easy to put down or pick up at a moment's notice, so long or short sessions are both comfortable ways to play. Factorio is worth many times its price and is a fine addition to your library.