This book is in a word, awesome. It is wonderfully written and tells the story of a tough corporal and his friend, Arlene, who must fight an endless army of alien zombies and demons who have infested the moons of mars. This book is very fast paced, very action-packed, very bloody, and very gory. The dialogue is great, and at times, the book is really funny. The different levels are described really cool in the book, and if you have played the game, you will recognize some parts of the levels. Another neat thing about the book is how Fly and Arlene learn about the demons and their intelligence and use it to fight them. Another cool thing about this book is that it is easy to read. The most complicated sentence in this book is probably, "The first demon at my buckshot and its head opened up like a melon." A few parts are a little cheesy though, like when the aliens use deimos as a spaceship and the aliens using genetic engineering to grow human clones for soldiers. That didn't have much to do with the plot of Doom, and I thought it could have been done without. Another thing I think they could have changed would be to keep the names closer to the video game. I mean, in the game there are zombies, shotgun guys, imps, demons, spectres, lost souls, cacodemons, barons of hell, cyberdemons, and the spider mastermind. In the book, they have the zombies, imps, demons spectres, but the cacodemons become pumpkins, the barons become hell-princes, and the cyberdemons become steam-demons! I guess I can let the shortening of spider mastermind to spidermind, and the renaming of the lost souls to flying skulls slide. Also, they didn't have the plasma gun or the chaingun! That sucked. But other than that, the book is awesome, with not much room for improvement! I've read this book to death and it is in tatters now!;-) Buy this book now!