I did an explanation about your erronous assumption, not an assessment! What lice did run over your liver today, chummer? That is so typical of native English speakers! Having no problem using English variants in games which even the boys and girls in Yorkshire would have problems to understand and expect non-natives speakers to understand this twaddle, but God beware if some developer is using some (even explained/translated) words from his own native tongue then it becomes an "annoyance".
As I wrote before, that might be your experience, but as far as slang words go, Ocean´s are not really rare. Might be a regional dialect thing, so in some parts of Germany these words could be more seldom, but here where I live, you can go into the street and ask someone, most will know his slang words.