Finally got my Doom updated and tried a few things in SnapMap.
First of course classic Doom campaign. It was pretty cool 2 levels I played

Not the same as classic of course, but fun nevertheless. I already forgot half of the secrets, but still remembered many

Also tried couple of users maps I got linked on Discord's Doom chat. Once was pretty cool, but my PC couldn't handle that many AI at once

Someone with better PC should have a blast.
Even though Doom doesn't allow you to use your own art assets, there is plenty of stock assets and scripting that allow creation of unique and fun experiences in Doom.