Inspired by the movie "The Chronicles of Riddick: Pitch Black" where (without spoiling too much of the plot) aliens only attack when it's dark, and when they do, it's in nigh-unstoppable numbers.
Unlike the zombies in Dying Light, which function during the day, and simply become more dangerous at night, the aliens will be made completely UV-sensitive (not unlike vampires), such that they don't even spawn during daylight (and lose health rapidly should they be caught in it). The same goes for alien bases: they would only spawn "just before" the night starts (so that a player gets a glimpse of where they are for about 5-10 seconds) and would vanish "a bit after" the night ends, but without leaving behind any alien artifacts in case they are not destroyed by the player. This means that in order to get artifacts, a player would have to battle hoards of aliens in the middle of the night and then raid their spawners before these disappear.
Some optional additions:
- Spawn a neutral "abandoned geological station" structure somewhere not too far from the starting area, the discovery of which (and possibly its connection to the power grid) will change it to the player's team and provide access to a timer that says Night coming in: XX:XX so that one could get ready more efficiently. This station will be destroyable by aliens (possibly a priority target?) and in this case another one will be spawned in its stead, in a location farther away from the starting area.
- Have a configurable number of moons, which would dictate the frequency and length of nights.
- UV flashlight + granades that are upgradable via research.
- UV light posts, that are triggerable by the player either once per night, following some "charging" period, via some wire condition, or etc.
- As the name suggest, during night time, everything outside the "lit aura" of the player's base becomes completely hidden behind a "pitch-black fog of war", in which the terrain itself can mutate overnight...
- Turrets will only be able to fire at things that are visible (aka "withing the lit area").
- Meteor showers / alien dropships falling on your base.
I decided to write this after reading one of the negative Steam reviews of Factorio, that talks about the "bubble of comfort" that players seem to reach, after which they're pretty much invincible and it's just a matter of time before they win. A mode such as this will arguably keep players on their toes throughout the experience.
