Take a 1000 zombies... a bunch of samurais....
LOTS of guns...
and rughtly olympic swiming pool of blood
and ad something quircky like a samurai sword with a lasersight
and make shore you avoid any type of plot.
then you have the recipy for versus.
its a japanese action movie that gives you the impresion that there trying to be serius but at the same time its creams comedy ^_^