What is The Fire Rush?

If you look at the bottom part of the screen you will notice a bar that says 'Fire Rush!'. As you progress in your playthrough consuming creatures such as animals and humans this bar will slowly fill up and once full your dragon will breath fire on any creature it sees while you roam the sky and adding it to what it has consumed so far.

If you survive long enough to go through eight normal Fire Rushes you will get a Mega Fire Rush which once unleashed when your reach your eight Fire Rush will release an inferno that incinerates all in your dragons path regardless if they are enemies you normally wouldn't stand a chance against in your current size. Make sure you take advantage of the Fire Rush and Mega Fire Rush whenever you have them to defeat mines and minibosses.