I have a lot of ideas when it comes to worldbuilding. I have always been a fan of science fantasy (combining both tropes from sci-fi and fantasy), but I feel like most works haven't embraced both genres to their fullest potential. The original Phantasy Star series is probably the closest because they weren't afraid to actually call magic "magic" instead of "the force" like in Star Wars.

I plan on using these ideas for my dream game (or series), but I'm posting these worldbuilding concepts anyway just in case I never get to creating the game, and I just don't care if other people use these ideas. They most likely have already been done before (in fact I know some of these ideas have been done before). I'm using AI to generate these concepts because I suck at drawing.

Anyway let's begin. First off, I think alien worlds should combine both ancient technology, futuristic technology, and everything in between. Technological progress isn't a linear path, so you shouldn't assume that aliens go through the same technological progression as we do. They might be flying interstellar ships, but they might also still be wielding swords and bows. So you can have spaceships flying over medieval style villages or even mudhuts. Star Wars has basically already popularized this, so this should be a no-brainer, but you can always take it a step further. For example, replace lightsabers with steel swords while still having space travel.

Another idea I had (which was already used in the Disney movie, Treasure Planet) is to have wooden ships flying between planets and stars. If certain alien species are capable of magic, then they can achieve low-tech space travel.

Gas Giant planets can have floating islands or even continents in them, kind of like the main setting of Skies of Arcadia.

Star Wars popularized wizards in space. I think we should also have witches in space. We can have alien witches flying between planets on their broom sticks.