Deadside Shotguns
After you get off the tram into the Cathedral of Pain, go straight and on the left will be a ramp that leads down to a flow of coals between the two platforms. Run on the coals to the left until you get to some rotating spikes. Keep following the path until you find a hole with a pole sticking through. Fall on the left side.It should say"Cheat Activated". In your inventory there is a book of shadows. You can activate a cheat called "I like Deadside shotguns" Use the pad, not the stick to turn it on. Now you can use the shotgun on Deadside!
Mystery Solved
If you look on the map you will see a door that requires ten power section, and says mystery. After you collect all 120 souls, yep every last one, you can go open the door to get what..... a second violater. Very usefull in destroying Legion. You just take both violaters and hit him until he stops moving around. Then whip out the Deadside gun and finish him off.
Play as Deadwing
To play as deadwing when you get to the Playrooms go to the room with the pool table. Jump on the pool table and it will activate the cheat and give you the shadowbook.
Play as Duppie
Go to the part in the undercity where you get a teddy bear save. Go fowards and right a bit and kill the gun guy on the slightly higher ground and then go to where he was. Turn right and go foward and you should see a sort of curved pipe. Jump as far as you can and it will probably say cheat active. It worked with me. You dont have to completely reach the pipe for it to work, just get close to it.
Secret of the Baton
Stand in front of one of the alters that has fire rising from the center, the type that seem to serve no purpose. Activate the baton. You should warp to a previously inaccessable area.
Wireframe Mode
To access Wireframe Mode in the "Book of Shadows" goto Mordant Street, Queens and head to the top floor. Head inside the only door on the floor and go right. When you round the corner you will notice two odd looking floor panels. Jump over these and a message will appear on the screen saying Cheat Enabled. Now check your inventory and access the Book of Shadows (Note: If this is your first cheat the book will appear in your inventory now.)