Putting on headphones and playing something, for 5+ hours with almost no chance of interruption is great, whos gonna call you at 4am? Is that parcel you ordered likely to arrive between 10pm and 5am, absolutely not. Its not healthy, but a great way to get lost in a game, long gaming stints are supposedly dangerous, gaming with the lights off is bad for your eyes, (I do usually end up turning the lights off, it does really strain after an hour or so!) but is, you know every once in a while just spending a long stint playing your favourite First person shooter or a game like skyrim really gonna impact your health that much, I doubt it but I am also not going to try and find evidence! (for or against)
Obvious Downsides to gaming at night are, people around you may be sleeping, you might end up not getting sufficient sleep at all and if you must work/ school whatever the next day your gonna be fatigued so you gotta be sensible, and keep in mind that getting your sleeping pattern back on track is hard its like getting jet lagged essentially, if you have ever travelled somewhere with a big TZ difference it really takes it tole on you, especially if your travelling for a long time (long distance flight with a transfer in between) its kind of like that, you essentially lose a day getting yourself back to a regular sleeping patten, thats a downside to working nights, I work a friday and a saturday night, but essentially lose Sunday as I am too tired to do anything but must try and stay awake to be able to sleep through to Monday morning and spend the week like a "normal" person.
We live in a 24 hour world, dominoes deliver to 5am, alot of supermarkets are 24 hours (thankfully not the one I work in!) you don't have to watch TV live,
If you have a few days off work/ school and no commitments over the coming days, locking out the world and playing and getting lost in some games is one of the best experiences in life. Does that make me sad? probably,
don't care tho.