If you haven't checked out the Aliens mods available for the original Doom, here's another reminder of why you should.
Modder Kontra Kommando has been busy modding Aliens into the original Doom for a while. Those efforts are still worth checking out, but the crowning achievement of his efforts so far is Aliens: Trilogy.
Trilogy is a rework of his existing mod, Aliens: The Ultimate Doom, but with sprites from another total conversion called Aliens Trilogy. Aliens Trilogy didn't have the best controls back in the day, so combining its look with Kommando's existing mod is like a match made in heaven.
The mod also has faction fighting, with predators squaring off against Aliens and marines doing their best to not get eaten alive by the others. It's an impressive amount of work, and there's still more content to be added.
Aliens Trilogy (UD) hasn't been released yet, but you can get a taste of where things are going with Kommando's previous Aliens mod mashup, Aliens (TC) 2017.