Doom Zero is a megawad which adds 32 new levels to Doom 2. It’s just been officially blessed by id Software and Bethesda which is how it ended up on my radar. 90s first person shooters hold a special place in my heart and from my initial playing I’m incredibly impressed with the level design and flow. The video below is my first time playing so it’s interesting to observe how I cautiously proceed, note my instinct to target the hitscanning monsters first.
If you have the original Doom on Steam you can easily install the mod from within the game itself.