Cool project 
Tried out the latest demo and if you keep on holding in the left mouse button and the jepack runs out of fuel, the character continue to stay in the air, every second or so the jetpack gives off a flame burst or the displayed fuel value is -1. A -1 fuel value is obviously not correct and if there’s no fuel, then the jetpack should not be able to give off flame bursts still and and there also would be nothing keeping the character in the air and so he should come down to the ground again