I got to level 13 time: 17:26.s
Do you think increasing floors have anything to do with the difficulty or it's only the time that matters? I usually die out in floor 6 or 5 (because I usually explore all of the rooms even after finding the 'next-level' room) so couldn't really figure that out.
I know it's been 8 months so it's highly unlikely to remember it, but were you able to reach a very high floor number again and still remember the correlation between floors and difficulty?