The AUS name is "Startale".

The AU is normal, except taking on the theme of space. Kinda like Outertale.

Gaster is still a mystery in this AU and did NOT make Sans and Papyrus. Alphys made them, therefore she is like a mother.

Sans in this AU (star sans) was made the show the underground what space and galaxy looks like, Papyrus was made as his counterpart to protect him from his low HP and defense.

Star Sans is afraid of water.

Yes.

Water.

Papyrus has both improved in the kitchen and in the puzzles.

I don't know what do add here, add questions in the comments.