So I though about a nighttime setting like you could change the day worlds to night meaning sun shrooms have more use than Dark Ages, the could be a night button on the level select screen when in a world, but Dark Ages doesn't need one cuz it's already Night.

This is an idea and it would not change the levels, but a challenge and make the mushrooms more useful

(The button could look like a moon and pressing it you turn it to night background and the levels would be night, dark ages doesn't need one cuz it's already night)