Short answer
The useful part first.
GRAIN ROT released for Windows PC on Steam on August 7, 2026. The official US base price is $9.99 USD; Steam showed a 10% launch discount at $8.99 USD when checked on August 10, 2026. Regional prices and the temporary discount can differ.
Release and store facts
Is GRAIN ROT free?
No. The full game is a paid Steam release. Older demo information or pre-release price guesses should not be used as the current purchase price.
Do co-op players need separate copies?
Yes. The official FAQ says every player needs their own copy. The store page lists online co-op, but does not list Steam Remote Play Together.
Price freshness note
The dollar amounts above are the United States Steam prices visible at the checked date. Steam can apply regional pricing, taxes, or later promotions, so confirm the final amount on the official store before purchasing.