do you have any tileset that would work with this/a recommendation?
Viewing post in Kosmonaut - player spritesheets for GB comments
You can have a look at this game: https://godai78.itch.io/europa-rescue
All the resources for it were made available on GitHub: https://github.com/godai78/europa
You may use them on a CC-BY license.
You need to download the background files and put them in the assets/backgrounds
folder of GB Studio to be able to use them in game. If you’re using any other game engine, then it should be similar.