If you asking me, no i didn't unfortunately. Nightmare is extremely hard difficulty, but i like it a lot because its so much fun. I've played on lower difficulties and its a little bit boring for me, maybe because i have played both games many times on UV and on lower difficulties, no idea. I've reached to E2M6, and i cannot beat this map its just so hard. I tried soo many times, maybe like 30 or something and still nothing. I can get successfully all the keys, but when i go back to exit the level, soooo many monsters are there and i just cannot kill all of them i don't have enough plasma cells. And i just gave up. Then i looked decino gameplay on this map and he completed relatively easy. I know that he's a good player, but he beated that map with 100% everything. Maybe i'll come back to complete it soon, but i'll see. I probably have a skill issue.
What about you guys?