A reference to a type of old-time slapstick humor reminiscent of serious but clueless people slipping on banana peels, causing a surge of wildly insensitive hysteria on the part of onlookers.
His whole being, starting in his early youth, was rooted in banana slapstick reality and this caused him to feel like an alien in this day and age.
Used to describe a motion picture with a suitably healthy dose of humor and gore. Derived from splatter (for blood) and slapstick (for comedy.
If you witness a flick were an arm gets cut off and gives the finger afterwards, or a priestkung fu kicks the heads off a bunch of zombies (as in Dead Alive-) those are prime instances of splatstick at its finest.