Thanks everybody for your interest!
@ Refresh Games: Found the information i was looking for, but I didn't get it to run now. Seems to be a bit different on various GBDK versions.
I'll learn how to make music for GBDK (and maybe directly in C) until the next gb jam. For sure! :)
Would be fun to make some C stuff. I always like to learn something new.
@ Carnivus: That's not really what I am looking for.
If I'd like the game a lot I'd do, but I think might get a bit hard until the deadline. Cause I have to work the next two days. Sorry.
If you just need some sfx, maybe I could do that on sunday.
@ Indiana-Jonas: That's not what I am looking for as well. Kind of - like what I said above. But I think there are tons of people that can do "wav/aiff/flac/mp3" chiptunes you could grab from.