On my game when i play on firefox the sound stutters and sometimes the game lags a bit,I'm not sure if it is because of my game but when i play it on chrome it works perfect.
Its specially bad on big levels and water levels,and its not related to audio size(i think) because i changed the WAV on the water level to a compressed MP3 file and that didn't fix it,when i remove water tiles the game runs better but the audio still stutters sometimes.
This also happens in the editor but its less noticeable,not sure if its a firefox problem,a pocket platformer problem or something that only happens on my game.
I made an improvement. It might not be perfect, but maybe it helps a little with firefox rendering. In general it's not a problem on your side. Appearantely firefox rendering implementation is just worse than chrome. So i would recommend doing everything in chrome, and recommend other people to play your game in a different browser than firefox.