http://www.videogamehouse.net/tunnelsdoom.html
Your view as you go down the hallway where you can encounter fountains or shrines that can empower or diminish your abilities...or you can opt to enter the doors.

Your view as you are in a room and in combat with the baddies.

Once you retrieve the king and orb (must be done within reasonable time limit or the king suffocates to death in the safe), you will face many wandering monsters going after you as you go down the hallway. No longer can you rely on the halls for relative peace.

There's an option to use the map to help you navigate. When you enter a new floor, the map is pretty much bare. But once you get through the floor, it shows where you have already been. Overall, this is a thinking game, rather than a reflex game like many of today's games.