World War Z, Torminator X Punica and Figment are free2play on Epic Games.
Did you get The Stanley Parable (And watchdogs) from the EpicGamesStore? The Stanley Parable is an awesome source-mod-like game where you have been put into a building completly alone with a 4 dimensional voice telling you what to do. Really awesome game.
The core of this game is basicly "Which of the 3 doors will I go through?" (no shotery or jumperino and stuff like that).
Therefore it can be a good option to look walkthroughs on youtube.