I did actually beat this game back in the day.
This game is really hard core, and lasted me a while
Some tips.
1) shooting normal looking walls in the right spots will help you out. often this is the only way to get a clue.
2) Locked chests are not random, and can contain ANYTHING! even the correct exit!
3) TO kill the dragon, attack one head at a time.
4) If you reach world 4 with 0 keys, start again from your last password. This is because there is no way to gain a key in any of the rooms in world 4 before the first clue room, so if you've lost your earlier password you have to start ALL OVER! NOte: it's very easy to run out of keys in the final stretch of world 3 if you are not careful.
5) No password will take you beyond the first level of the last world. you can take advantage of this and build up your suppliesby reperatedly beatin gthe first level and beating the treasure room for a new password..
6) The first charater of your password determines your vault key. knowing this you can look it up online if you missed a clue (cheater!)
7) a simple way to double your supplies. start a two player game, and enter same password for bot pplayers, then kill off player 2, and grab his stuff.
8) As you will very quickly discover, different exits can go to different rooms. but in such a case, the correct exit is NEVER randomly placed.
9) there is exaxctly ONE level that has unreachable stuff. you will know it when you see it (by the multtple rooms positively PACKED full of food, poion, and powerups that never open no matter what you do.)
10) playing alone the Elf is the ONLY character that can pass the world 5 treasure roooms every time. when playing two player, two wizards/valkries can play it. Under NO circumstances play the warrior. Even in a two player! PS: NO character can pass the massively unfair world 4 treasure rooms all the time. but being the elf helps...
11) Magic is your friend. but make sure all players are STILL when you use it, or it tends to fail. This is why the elf and wizard are so good. Plus wiz with extra shot power kills all normal enemies in one shot! Balance? who cares about balance?
12) don't forget to grab the orb! it's AFTER the exit!