How hard is French A-Level?

Unless you are very passionate and are willing to put a lot more extra hours outside of your normal subjects don't do a language. It is far more meticulous than many other subjects and on par with the sciences in terms of respect. The jump betweeen GCSE and AS in large and many people I know are failing due to thinking they could get away with GCSE style preparation for exams. Just make sure you have the passion and you'll be fine.