Costume Quest 2 is on Game Pass
Doki Doki Literature Club is a free-to-play title on Steam and itch.io (Plus is a paid game that is also eligible for this)
https://store.steampowered.com/app/698780/Doki_Doki_Literature_Club/
https://teamsalvato.itch.io/ddlc
KCF can't actually be a real person but he is - greengravy