By scanning over this image, can you immediately tell which are hills and which are flat? Don't look too hard, just try to guess immediately, as if you're playing the game and need the info readily available. When I look at this picture, this is what I see: Spoiler : Well, I'm wrong, there's only three hills. I know everybody knows hills are hard to see, but now that they've been polishing certain aspects of the game, such as adding wonder and city-state pickers, perhaps it would be the appropriate time to rework hill tiles. Is this terribly game-breaking? No, but it is annoying, and it does disrupt the game whenever one accidentally moves onto a hill with bad enough consequences that you need to reload the save. Furthermore, I can never tell, by simply looking at the map, what the most defensible positions are. Hills with forests or rainforests have a bunch of tiny stones that differentiates them from flat tiles, but again, you still need to squint. So in the end the only solution is to use the Hill filter, but you'll not have that on all the time, and you'll still make mistakes. Besides, I don't think one of the basic terrain types should need to be highlighted in order to be properly differentiated. Nearly everything in this game is distinctive enough, so it makes no sense for hills not to be. PS: I know the Environment Skin mod makes them clear. I use that mod sometimes, but I also enjoy Civ VI's art and would just rather have proper hills in this art style.