Not every German word is that long. In Scrabble you get seven tiles, so, combining with a letter already on the board, you can use eight letters in one play. However, over a number of plays you could build up even longer words by adding affixes to words already on the board. If this site is anything to go by, they do play Scrabble, and you can use up to 12 letters to try to find a word there.

Still, they do have a lot of long words. Twelve letters? Wow! Does anyone know what that word means?

Fußboden: floor
Schleifmaschine: grinding machine
Verleih: rental agency (verleihen "to loan" is cognate with English "loan" and "lend")