Most of these, if not all, have already been posted including by you. If your goal is to centralize the freebies then maybe create a pinned topic for Twitch. Just to list a few:
https://phatwalletforums.com/topic/25642/twitch-prime-pcdd-games-for-august-2020-shaq-fu-a-legend-reborn-warsaw-treachery-in-beatdown-city-chroma-squad-blazing-chrome
https://phatwalletforums.com/topic/25579/7-free-pc-games-for-twitch-prime-members-free-to-prime-members-twitch-claim-by-12-31-reg-71
https://phatwalletforums.com/topic/25482/free-pc-game-neurovoider-reg-14-twitch-prime-free-for-amazon-prime-members-claim-by-8-21
https://phatwalletforums.com/topic/25281/free-pc-game-dungeon-rushers-twitch-prime-thru-8-14