Luciferase

I think Nightmare Moon's world would sadly not be very happy... While her universe is comparatively safer to the rest of the war-torn timelines we saw in season 5, Luna's whole reason for becoming Nightmare Moon was due to ongoing neglect that caused her to spiral hard into envy, of which sadly manifested in a distorted ego and superiority complex. So long as she's like that, the poor mare is sadly in no state to nurture an entire nation since such a burden naturally comes with a fair amount self-sacrifice. Rather than loving them unconditionally and providing them their own chances to shine bright, Nightmare Moon will only love her subjects so long as she feels she is getting the love and admiration she deserves, which could have potentially disastrous outcomes if she, at any moment, feels that her subjects aren't admiring her enough or there is even the littlest of push-back against her, real or perceived. Even if her Equestria seemed relatively fine when we saw it, I can't imagine it lasting very long under her rule before it either fall apart because her subjects couldn't keep up with her unstable demands, or just plain fails to thrive due to the oppressive nature imposed on it. As for the rest of the land, no doubt her eternal night would have some pretty serious consequences. Equestria would need an entirely new food and agriculture system for starters, and I can only imagine how cold it will get without the sun to help provide warmth. Not to mention the sheer number of health problems that would arise from the lack of the sun, since so crucial for good health, such as maintaining healthy sleep cycles, vitamin D production + calcium absorption, and release of serotonin and endorphins (Its why ppl have such a hard time sleeping and feeling good in the Winter). Plus, who knows what monsters could be running loose without harmony and all that jazz to normally keep them at bay! Those first few years would not be easy and would need a LOT of magic and improved technology to counteract it, and even then could still cause a good amount of problems in the long-term To put it bluntly, Nightmare Moon's world would be one heck of a nightmare I'll show myself out

Man, 15 years... I still remember seeing the first episode on tv way back in elementary school when it was still on The Hub, and now here I am all grown-up and graduated from college. Where does the time go?? For FiM specifically, there's two 1-hour-long specials: Best Gift Ever and Rainbow Roadtrip, which are both on the official Youtube. They're self-contained stories so you can honestly watch 'em whenever without worry of spoilers! There's also a mini-series called "Friendship is Forever" that takes place after season 9, but its mostly a just clip show recapping past best moments. Other than that though, that's about it really. The grand majority of shorts and specials went to Equestria Girls after that series finished doing the initial 4 movies. If you ever tackle Equestria Girls after FiM though, I recommend em! The first movie was a little rough, but the rest of the series (movies and specials) were all surprisingly good!