Enter "QQQQ QQQQ QQQQ QQQQ" as a password and ignore the "Incorrect Password" message. Then, a "Debug" selection will appear on the option menu. Level select, all weapons, invincibility, and monster targeting may now be accessed.

Enter "NOCLIP" as a password to pass through walls.

Begin game play on level 3, and reach the area before the elevator, near the end. Platforms with two enemies should be over your character at this location. Kill them, and a cage behind your character will open, revealing armor. Shoot the wall behind the armor to find a warp that will transport your character on the platforms. Go to the platform that contains missiles, face to the right, and shoot the wall. This reveals a secret hallway with another warp, that is actually a trap. The floor will open up, revealing lava. Sidestep to the right and run to the warp as fast as possible to reach the Ziggurat Vertigo level.

If you want a very high Agility stat to avoid enemy attacks more often, there's a very simple way to do it. First, head to an open space - in Brannoch, Melrode and the path along Melrode Monastery work nicely - and start rotating the control stick so that Brian will continuously run in circles. While you're rotating unplug the N64 controller you're using. If done correctly, Brian should still be running in circles. The more you run, the more Agility you gain. With this method you can leave the console on and gain a nice amount of agility without any work.

Play until you reach the desert section. Explore the southeast part of the desert with no walls until you see a gem floating in the air. Touch the gem to be teleported to Shamwood, a castle that doesn't appear on your map and is full of items.