HTML5 audio sucks right now. It's a known problem (that might even be fixed in Chrome 13), but yeah, it's not ideal at all for the moment.

Further reading: http://www.phoboslab.org/log/2011/03/the-state-of-html5-audi...

<audio> isn't meant for short, repetitive clips (which is what games do). There's a new API being built for this need, can't remember the name of it right now.

That's a rather absurd theory, considering that making the free online version work well on iOS would reduce Apple's income from a very, very popular iOS game.