Video game project to spark the mind during WBTB

Hi,

I plan to build a videogame to play with while WBTB.
The goal is not to dream about the content of the game, but just to have a brain activity during the 20mins-45mins period.
The thing I enjoy the most in dreams is to explore new lands, places, cities, so it would be an important part of the gameplay "pure exploration" (As for exemples games like "Journey" on PS3, or "Proteus" on PC).
You probably heard of "LSD - Lucid Dream Emulator" which is some freaky and old graphics, it's not really the direction which inspire me.
I prefer things like this : Real-Time Grass Rendering on Vimeo
I do not talk about the technical aspect of making a game, but I have choice now between 2 games engine (Half-Life 1 or Morrowind).
The choice of the engine would depend if the game is mostly indoor or outdoor.
I had the idea of making this game for myself, and I thought that It may would interrest other people, so to orient me in the choices of the "art" side of the game, I'd like to know your answers about this :

(About exploration...)
Flying or walking ? or combine of both.
What kind of mood for the sets : surrealist as Dali's paintings ? Freaky ? Psychedelic ? Simple ? Other ideas ?
Music and sounds ?

Thank you

Flying and walking and psychedelic. For music how about this song. I think trippy stuff would definitely best especially things like the scene changing when you turn away and look back. Eerie stuff.

Ok for walk-fly, and trippy.

I am still not conviced about the interrest of making such a game only for WBTB.
I rode in basics of LDing to avoid screens few hours before going to bed, because of blue lights do not help to go asleep.

Also I found this program which is cool to make busy-mind for few minutes : Space Engine - Home page

Anyway I am going to make such a videogame, even if it's not for WBTB, I will be dreamish and I will share it here :)