Factorio is still in beta. But since the newest release (as off 28 of august 2016) some annoying features (or lack of features) have been addressed. Now online play works as one would expect with a lobby of hosted games that you can join. Now it is easier to use mods in the game witch is good to keep things new and exiting (though this game is NOT feature lacking).
The game itself is the farming game of farming games without farming. Instead of digging for minerals like in minecraft. In factorio you make a robot that digs for you. Instead of crafting like in minecraft you make a robot that crafts for you. The hard part ot the game is to make all the robots needed to make the stuff you need link together in the most efficient way. Crafting in Factorio comes in steps.
step 1: build a mining drill that mines your minerals
Step 2: Build a furnace that you can process the minerals in
Step 3; mine coal for the furnace
Step 4: build an automatic transport system that does it so that you do not have to manually work (this is important as your factory grows).
As the game goes on more and more steps of processing of materials is needed to create the products you need. This means that the game becomes harder as you progress and it all boils down to a good game for people who like thinking games. Add creeps that destroys your base if you aggro them with pollution and the game can be really hard. If you are nerded out on the redstone creations in Minecraft this is definitely for you.
If you don't like long game sessions and time consuming games KEEP AWAY =).
Max Mildh