thank you Shashwah for your answer!
I agree with you that most of the "roguelike" elements could be used into a space themed roguelike, but I'm wondering if space can add some other gameplay elements, like for example zones without gravity or zone without oxygen, where you can advance only with a tank of oxygen (if player decide to use an human explorer of course!).
what do you think about it ?
I think you're confusing theme for mechanics. How is a zone where a player takes damage without an oxygen supply any different from a zone in a fantasy world with a gas cloud?
The only real differences that sci-fi offers you is the possibility of great distance (and great dissonance) between levels, assuming you include some non-realistic breaking of Einsteinian physics.
You can also go deep into the lore and drag the player along with you so that they don't notice the existence of magic (EG: Mass Effect series) but honestly it's all the same thing, don't kid yourself.
More meaningfully, I think, is to set a challenge for yourself - find one mechanic that necessitates sci-fi and cannot be
reasonably replicated by medieval/fantasy. If you can find that mechanic, make a game around it. I include the word 'reasonably' because by definition 'magic' excludes reason, so.