Northern Lights

Yes. Northern Lights is free to play on Steam, so there is nothing to buy to start playing.

The minimum requirements for Northern Lights are: Windows 7, GeForce GTX 970, Intel Core i5-4590, 4 GB RAM, 3 GB storage. It runs on Windows only. The recommended specs are in the System requirements section.

No. Northern Lights is a single-player game.

Yes. Northern Lights is the full base game. You need nothing else to play it.