The procedurally-generated dungeon and vast array of possible items gives immense replay value. Some games you'll find a good weapon early, other times you'll rely on wands or potions, or some combination. Sometimes in sheer desperation you'll read a random unidentified scroll... will it be a scroll of fire that incinerates your clothes? Will it be a blessed scroll of teleportation for the ultimate escape?
This is one of my favorite rougelikes on android, don't see it talked about much.