The lobotomizer? That’s a World War Z reference. The book anyway, never saw the movie. Basically the new military started converting their entrenchment tools into weapons, sort of an axe shovel. Thus why you can dig and cut down trees with it.
It was already mentioned, but boomers, spitters, smokers, and hulks are L4D zombie types.
Edit: The hospital scenario could also be a 28 Days Later reference. Seems somewhat fitting. The Walking Dead works too though.
Edit2: Also, the towel description is a Hitchhiker’s Guide to the Galaxy reference.
In addition to the above WWZ reference, Max Brook’s Zombie Survival Guide can be found. Ironically the game describes it as useless because of misinformation (the guide tells the reader that games and movies are filled with misinformation).
The Samurai Book’s description is a 7 Samurai reference, just as the Western Book’s description is a The Magnificent 7 reference. The adventure novel description is a nod to Joseph Conrad’s Heart of Darkness. Hitchhiker’s Guide to The Cataclysm. Another reference to HGTTG. The Guy Fawkes Mask’s description is an Anonymous reference. The S&W 629 makes a small “Dirty Harry” reference, and the .44 Magnum ammunition description mentions the movie by name. Finally, the last I think I know is that the Grabboids are a “Tremors” reference.