Hello dear
@Sunniestcat, this is not a bug, you have the minimalist mode enabled on your game because of that you see all the terrains as in the pic on the right.
To fix that problem you have to disable the minimalist mode, here how you can do it:
1. Go to the options panel in the game
2. Just uncheck that
I hope you can keep enjoying the game and thanks for reporting your issue.
Thread closed.