Beware of boulder traps, spike traps, ceiling magic traps, gnomes with lightning staffs, goblins with fire staffs, trolls on the first few floors, scorpion paralysis, insectoid spray acid, demons, crystal golem slams, cockatrice(s), low perception, and playing by yourself. This game is excruciatingly punishing and equally as rewarding. I've gotten more enjoyment out of the $20 basegame than I have most $70 AAA titles.

Seriously, make some friends and buy the DLC please.