Phonetically, French is quite different from English (equally stressed syllables, no diphthongs, nasalized vowels, unaspirated stops, uvular r).
The only problem with pronouncing German might be its ch (ç or x) and r (which varies with accent). It's also easier to work out how to pronounce a German word from its spelling.
Even in the written form it's absolutely impossible for me to decipher, it might as well be a completely different language:
>HWÆT, WE GAR-DEna in geardagum,
>þeodcyninga þrym gefrunon,
>hu ða æþelingas ellen fremedon!
The language evolved so drastically over the past thousand years that his germanic roots are buried pretty deep. Nowadays you're likely to find more cognates in a french text than in a german one.
Meanwhile I can find french texts even older than Beowulf and still understand the general gist of it. See for instance https://en.wikipedia.org/wiki/Sequence_of_Saint_Eulalia#Text . Even if you don't speak french comparing the original and modernized french version should be enough to convince you of the similarities:
>Buona pulcella fut eulalia. (Bonne pucelle fut Eulalie.)
>Bel auret corps bellezour anima (Beau avait le corps, belle l’âme.)
>Voldrent la veintre li deo Inimi. (Voulurent la vaincre les ennemis de Dieu)