How can you beat infinity on the ipad game 'oven break'?

I've been playing the game Oven Break constantly on my iPad and it is tons of fun. However, I beat the easy and challenge levels and i have played the infinity level many times, but unlike the other 2 levels, it has no meter of how much longer i have to beat the level and I find this really annoying because I want to play the christmas level. Is there a way to beat infinity???