Changed the look of the world map

I'm currently working on assets for world 3 (most tiles and a few of new enemies are ready to be implemented) and while making a map screen for it, I've decided to improve the entire map visually, but also to push the fog of war a bit further away so players can see one world ahead, and not just the world they are about to play. I hope this will provide additional motivation for finishing unlocked worlds and continuing with the game.

Demo has been updated to the latest version.