The GM's assumption is that Dungeon Fantasy is a slightly adversarial game. He's built a dungeon that is intended to kill the delvers; the delvers are trying to break the dungeon. The odds should favor the delvers, but sloppy or careless play will get people killed, maimed, or otherwise rendered useless.

The GM has stocked each dungeon with roughly $80000 in valuables. Some of it will be hidden, some of it will be hard to recognize, and some of it requires special skills to get at. Some of the loot will need to sold, which will possibly diminish the final values the delvers get from it. Played perfectly, you'll come out covered in riches, with nice magical toys. A casual run and poor choices will likely get you only $6000, some decent magical items, several dead or cursed delvers, and a very pissed off Polisberg Town Council.

The GM came up with most of the obstacles before you guys created your characters, so the dungeon is not tuned to your abilities. On the plus side, that means there aren't any hose jobs designed for you specifically. On the minus side, its entirely possible you're lacking skills you need to survive and prosper. That's Dungeon Fantasy for you.

A final note: the commentary on D&D4th has inspired a lot of thought about what a "fun" combat is. Do not expect to be able to kick down a doors, surprise a handful of goblins, slaughter them without mercy, and then move on to the next room where there's another bunch of unprepared goblins. Expect to be ambushed, to be outflanked, to be surprised, to be attacked on unfavorable circumstances, and to have to deal with enemy reinforcements.