https://www.gog.com/promo/20210909_cathedral_sale

And GOG silently added Shadowgate to the Weekly Sale:
https://www.gog.com/promo/20210906_weekly_sale

https://www.gog.com/promo/20210910_reventure_sale

GOG announced the new game but mentions nothing about discount.
https://www.gog.com/promo/20210910_launch_promo_kraken_academy

https://www.gog.com/promo/20210913_death_taxes

https://www.gog.com/promo/rpg_month_flash_legend_of_grimrock

https://www.gog.com/promo/20210917_loop_hero_ost

https://www.gog.com/promo/rpg_month_flash_kingdoms_of_amalur

https://www.gog.com/promo/20210917_voodoo_kid

https://www.gog.com/promo/20210917_smart_city_plan

https://www.gog.com/promo/20210917_phoenotopia

https://www.gog.com/promo/20210920_urtuk

https://www.gog.com/promo/20210920_papetura

https://www.gog.com/promo/20210920_interstellar_space

https://www.gog.com/promo/20210920_hundred_days

https://www.gog.com/promo/handy_games_indies_paradise

https://www.gog.com/promo/rpg_month_flash_warhammer_mark_of_chaos

And GOG silently added Prison Architect and its DLCs to the Weekly Sale:
https://www.gog.com/promo/20210920_weekly_sale

https://www.gog.com/redeem/MANDALOREKUF65?at_gd=7B4940B421D34A433160E09CF8E4A9C0F4AF2A89&utm_campaign=adtraction&utm_medium=affiliate&utm_source=adtraction
Mandalore Gaming Discount Code for Kingdom Under Fire games, you will recive 65% discount in both games simply using the link above or introducing this code 'MANDALOREKUF65' in https://www.gog.com/redeem

https://www.gog.com/promo/20210924_the_uncertain_light_at_the_end

https://www.gog.com/promo/20210924_embracelet_anniversary