CEONSS

SOMA free for 11 hours. What ever that is.
https://www.gog.com/game/soma

The new Battletech game is currently free to play over the weekend (on Steam). Also 40% off if you decide to purchase it.

Not a game, but the steam controller is 90% off right now:

Unreal Tournament 2004 is not 90% off on GOG:
https://www.gog.com/game/unreal_tournament_2004_ece

rayman-legends for free insted ~20 € when you get it until 06.12.2019
https://www.epicgames.com/store/en-US/p ... gends/home

Wasteland 2 free on GOG - 28 hours left:
https://www.gog.com/game/wasteland_2_di ... ic_edition

Postal and Postal 2 free on GOG:
https://www.gog.com/game/postal_2?pp=df ... 8faaaf09be

Every classic Half-Life game is now free on Steam
For a limited time.

https://arstechnica.com/gaming/2020/01/ ... -on-steam/

Just open the menue and there will be a "Start Game" button.

Total War: Shogun 2 for free on Steam till May 1st

https://store.steampowered.com/app/2012 ... _SHOGUN_2/

Ashes of the Singularity: Escalation is free for two more days

https://www.humblebundle.com/store/ashe ... _deals_1_0