Metroidvanias/search action/another term that includes souls games that share aspects of exploration?

Search Action - going beyond the defining pillars of Metroidvanias

The half-way point between linear and open world games - analysing the interwoven exploration of Metroid, Dark Souls, Resident Evil, and more

How can designers support a mechanically limited non-linear progression beyond the mechanics themselves? How does a mechanically limited non-linear progression enhance exploration/emotional impact?

Enhancing the lock and key - How do interconnected environments, backtracking, and spatial reinterpretation enhance exploration

Enhancing the lock and key through player and environmental evolution

Engagement, emotional response, intended behaviour

Lock and key - Any obstacle and method to surpass it, door and key, door and switch, wall and bomb, gap and double jump, boss and strength

Evolving the world - backtracking, shortcuts, events, “state” (the options to the player for progressing)

Evolving the player - abilities, tools, strength, knowledge, confidence

Consider the player and character synonymous as the aim is for the player to be immersed in role playing the character?

Why does this need to be studied?

Factors - The methods and aspects used in the game

Criteria - How it can be measured, intended responses