Hi! After playing all three character classes a few times, I've got a few things:
Undead is very powerful, the resurrection is annoying because the high health and stats get powerful very quickly.
I have no idea what "Run 4" means in Library.
Also this is probably a skill issue, but I haven't been able to get to round thirty even when trying to spec a certain stat because the bosses surpass the stat seemingly no matter what.
That aside, great game! I love all the mechanics and variety. Looking forward to seeing updates!