As we noticed something interesting testing with @dtm, playing the same file with Flash Player 11 (Standalone) instead of Flash Player 32, makes the game slightly faster. You can see the speed difference in the following animation:

The in-game time is consistent with any Flash Player version, so from now on every run will need to show the IGT unless a rare exception is made for whatever reason. To activate the in-game timer, press the T key inside level 1. You just need to do it once, then you can exit the level and start again, the in-game timer will be there.