So bitcoin is bit-Münze ?
No; it's called Bitcoin - they just use the English word (but capitalised because it's a noun).
Meine achte Münze ist aus Gold.
While at an arcade in Hemsby I heard once u pressed the German introductions... Bitte die Münzen einwerfen
Münze is cognate with English 'mint'. The English comes from an Old English 'mynet', the German from Old German 'muniz', both from Latin 'moneta', whence also 'monetary', as well as the English 'money' via French from the same Latin word.