Aliens vs Predator 2 singleplayer custom map titled "Hades Facility III" aka "Alien Hades".
Map author: Alexandre "Lord_Hades" Vancomerbeck
Hades Facility III is the third and final entry of a series of maps built on the same map. In Hades Facility III, the player takes control of a newly born alien facehugger. The facehugger encounters the predator who just killed his family and looks to get revenge. The level design is exactly the same as Hades Facility I and II with the exception of a newly added outdoor area.
This map is technically broken up into three maps, although all three are on the same map/level. In the first the player plays as the facehugger and must find either a human or predator host. In the second level, the player is the chestburster looking for food and the third is a full grown alien (drone or predalien depending on who the facehugger used as a host). As previously stated, each level reuses the same map, but the final map has an additional outdoor area where the player must face off with the predator. The predator is ridiculously overpowered in health and will take a beating to bring down.
Once the predator is disposed of, the alien must eliminate the remaining marines and corporates inside the base and evacuate. I ran into a problem with this map with the evacuation. Once all the enemies are defeated, a cutscene is triggered to the alien's escape. However, for whatever reason, the predalien's cutscene glitched to waiting for the bomb to detonate every time even though there was plenty of time to escape. I even destroyed the bombs before the cutscene was triggered and this still happened. When I played as the drone the escape cutscene played out normally. Depending on how fast you are in escaping, you are awarded a star rating out of five.
Personally I think Hades Facility II is the best in this series of Hades maps, partially due to me preferring the human gameplay, but also because this map seems to be the most polished. Hades Facility III is longer and has more interesting cutscenes, but the glitched finale was a bit underwhelming. Nevertheless, its one of the best custom singleplayer maps for the alien and should be played if you haven't already.