This jam has an art requirement but it doesn't have a "excellent" art requirement
If you are not a natural artist, keep things very simple and abstract and focus on the game design instead. You can make a location out of abstract shapes if you wish.
I'm not an artist and I kept things simple when making location graphics for dinosaur island dx (the loading screen wasn't mine though). If I can do it, anyone can do it.
Please don't use digitised art (converted from a photo). It tends to look bad when shown at a low resolution and actually takes you out of the fantasy realm too.
Colourful graphics are the order of the day.
Good luck!
Chris