It starts out, “Hast du etwas Zeit fuer mich/dann singe ich ein Lied fuer dich/von 99 Luftballoons?”
Which translates as, “Have you some time for me/that sing I a song for you/about 99 ballons?”
And, that’s all I can translate off the top of my head. Heh. But, yeah, the German lyrics are kinda different than the English version.