There is No GreenDam

Yes. There is No GreenDam is free to play on Steam, so there is nothing to buy to start playing.

The minimum requirements for There is No GreenDam are: Windows 7, Intel Pentium 4, 512 MB RAM, 500 MB storage. It runs on Windows only. The recommended specs are in the System requirements section.

No. There is No GreenDam is a single-player game.

Mostly, yes. Valve rates There is No GreenDam as Playable on the Steam Deck: it runs, but may need some manual setup.

Yes. There is No GreenDam is the full base game. You need nothing else to play it.