hi!
actually i can set quality_modes to
fastest
fast
simple
good
beautiful
fantastic
so far so good, but is it possible to change
beautiful to → better
fantastic to → best
Not right now. Of course, if you disable startup dialog and implement quality level selection in your game, then you can name the entries as you wish.
hm, thank you, i will have a look at, maybe i can figure out what to do → dont forget as a newbie i have to learn → ¿UNITY¿ 
You’ll most likely use QualitySettings class from script.