Eichhof is the local brewery of Lucerne, Switzerland. Unlike most other large Swiss breweries, who were bought out by international enterprises, they still remain the largest independent brewery of Switzerland today. This accounts for the plot of this game: the enemies you're battling are all somehow related to other big breweries, like the castle of Feldschlösschen (the biggest Swiss brewery) or the logo of Löwenbräu from Munich, Germany. You have to fight them off in order to prevent them from buying out the Eichhof brewery.
Also, many of the bonus weapons you can buy in the shop are actual beers produced by Eichhof.
In the game's shop, extra lives are called "guttere", which is a (very) colloquial Swiss German word for bottle.
The Last Eichhof, being a home-brewed game, included several audio clips from TV shows.
Notable clips include...
...The infamous belch from Barny of The Simpsons. ...The brass fanfare from ABC Nightly News. ...Clips from Warner Brother Cartoons.
and an assortment of samples of people speaking German or English in context of the game. On the whole, quite within the free spirited design of the game.