Welcome to the Underworld, where you guide Mutt, the bad luck Litil Divil, through the Labyrinth of Chaos to retrieve the Mystical Pizza of Plenty. Our “hero” takes a fateful step through the Mortal Portal to prowl five hellish levels of treacherous tunnels with more than 50 raucous rooms of gameplay. Beware of killer spiders, bottomless swamps, ferocious furnaces… and crazed bartenders. And watch out! If you can't get Mutt to the Overlord, The Entity and The Servant will drag him to the Torture Room for a little fiendish fun.Go to: http://store.steampowered.com/ and download STEAM client
Click “Install Steam” (from the upper right corner)
Install and start application, login with your Account name and Password (create one if you don’t have).
Please follow these instructions to activate a new retail purchase on Steam:
Launch Steam and log into your Steam account.
Click the Games Menu.
Choose Activate a Product on Steam…
Follow the onscreen instructions to complete the process.
After successful code verification go to the “MY GAMES” tab and start downloading.