Turbo mode

[cameleon]

I finished the game at 'hard' difficulty, and started a new game at 'ludicrous'. I noticed 'turbo' in the top left corner, and the game running faster. I thought it was fun, except that the turbo mode seems to persist, and also be activated in collection mode (wouldn't this make it easier?), and for other players! Since these players have a different level of control of Gish (i.e. I'm a better player ) this is not desirable. Is this meant to work like that, or is it a bug?

Also, I managed to turn off the turbo using liberal amounts of starting a new game at another difficulty and restarting the game. What are the exact actions required to turn off turbo?