There is a limit somewhere, but I can't remember it off hand (and it may well change!) However, I'd suggest you seriously look at getting the size down either way - at 70MB chances are most people won't bother waiting for it to download before playing it even if you can upload it! Chances are you have a lot of wav files, if you convert them to mp3 (use Audacity or similar, it's free and easy) then the size should decrease dramatically.

Thanks, done and done! http://www.greenfoot.org/scenarios/4032

Wave files are uncompressed audio files, which makes them very very large. Mp3 uses a very nice compression scheme which allows for a lot more audio to be bundled into the same space. My Nightmare scenario uses over 100 different unique sounds, and each one has been compressed into mp3 for maximum space efficiency. AIFF is also uncompressed like WAV, so your best bet would probably be mp3 like me. All of my sounds uncompressed in WAV form would take 86 Mgb, but in compressed mp3 form they only take up 6 Mgb!