I developed a mod for Don’t Starve which adds alien invasions into the game in Lua. The mod spawns a number of crashed ships throughout the world each season so the aliens slowly take over the world. The aliens will only come out at night unless provoked but will attack you on sight.
It was an interesting project as I enjoyed programming the aliens artificial intelligence. The alien has several states it can be in and will always try to return to its ship before daylight. I also used Spriter to animate the aliens. The aliens were improved versions of the ones I created in Luneoids. You can view the mod on the Steam Workshop and the code on my Github repository.
An early version of the mod was reviewed in a mod spotlight: