small and clever productions explains how to create your next movie with green screens, Unreal Engine and Vive Trackers if you are on a budget.
https://hackaday.com/2022/06/04/make-your-own-virtual-set/
The oddly satifying snd.dev sports sounds and a library for UI interaction audio.
https://snd.dev
Flickgame might be the most minimal game engine out there.
https://www.flickgame.org/