We just released an update, this update includes some more bugfixes and the in-game store.

Features:
In game store added, with DLC for sale through Steam overlay.

Bug Fixes:
Crash in chapter 4
Crash in chapter 8
Crash in The Stars Are Left chapter 3
Crash when transitioning to next scene in Vietnam Rescue Mission
Added a popup to inform players how to re-enable the steam overlay during the GDPR popup if it has been disabled. This should stop players getting blocked at the start of the game