When you are playing in the Alliance Campaign, in the Chapter where Lady Vashj helps Kael escape from the jail, there is a secret. You'd better use the cheat iseedeadpeople to find the place.When you type the cheat search in the whole map for a place where 3 sheep (1 blue, 1 yellow and 1 red)are imprisoned, then go there. Kill everybody in your way and when you reach that place you'll see three buttons, 1 in front of every sheep. Then start pressing them randomly and eventually, a message will come up and say: "Bonus level unlocked. Finish this mission and it will start automatically." I think that's what it says, if I am wrong, sorry:)Well, when you finish that Chapter you'll see Kael and Lady Vashj speaking, then you'll be sent to the secret level. It's really fun! Oh, and you can play it again by choosing it from the Chapter choose screen. Remember, it's in the Alliance campaign!:)