GUX: Unfortunately, there is no precise definition of Game UX yet. However, it concerns what the player will perceive, understand, his interaction with the game and his level of engagement.
The Gamer's Brain: How Neuroscience and UX Can Impact Video Game Design
https://www.youtube.com/watch?v=rIQMqwsotzE&t=1s
https://www.coursera.org/lecture/gamedev-capstone/user-interface-and-user-experience-for-games-by-charles-roman-senior-software-NMCdo