Hey,
now my wad contains 2 maps: https://www.doomworld.com/idgames/levels/doom2/Ports/a-c/advent2, which are focused on tricky fights and good visuals (I do my best).
Map 1: Advent
This is a 1-1.5 hour long open map with lots of relatively short tricky fights. On UV there are around 1k monsters and most of them are imps.
Difficulty: early sunlust levels (I think)
Building time: 2 months
Music - Opeth, A Fair Judgement. Map is named after anot