Nintendo of America imposes a rather strict policy of “censorship” over video games. Japanese versions are purged from any hint at sex, smoking, alcohol drinking, graphic illustration of death, politically incorrect images, etc. Sometimes games with potentially offensive content were not released at all.
Filibustercartoons tracked down a copy of Nintendo’s content guidelines, typed it up and illustrated the differences between Japanese version and US version of games with plenty of examples.
The gorilla in Little Nemo was originally smoking a cigar.