Yeah, so, I'm not German (though I do speak it)...
The humour is not inherently German (i.e. there is some!), but it is funny. Very, very funny. Bully started with "Der Schuh des Manitu", and that was a poor German ape of Blazing Saddles... but this is different. For a start the special effects make you wonder how Star Wars I-III managed to spend their significantly larger budget. They're good. There's something almost British about the comedic understatement and dead-pan delivery. A knowledge of colloquial German is useful though.
The "icon" of the movie, the gay trio of Kirk (Kork), Spock (Spuck) and the other one (it isn't clear which Star Trek character he's meant to be), is the weakest point of the flick, but fortunately it is a minor intrusion. There is plenty of wit, spoofing and entertainment besides. Til Schweiger is excellent - a German Bruce Willis, maybe? Perhaps, as an Auslander, I find this movie more endearing than I should, but I highly recommend it.
Mopsgeschwindigkeit!