I was having a lot of trouble with the first boss but then bought the sniper rifle. even being a commando without the extra damage it took him down in less than one clip and on the first try. Hope this helps!
"Boss, why dont we just buy some guns instead of buying jetpacks? That way we can kill him before he gets experience and can easily kill us all?" asked the employed thug. the boss replied "Why do that? everyone knows a guy with a wrench and a jetpack is invinsible, idiot. Now order more jetpacks, i want this guy dead." the boss replied.
"Oops, i've lost all my marbles in a dark cave but dont worry, an invisible force will help me and he will use this single candle which provides minimal light and will go around searching for my marbles for free to make me happy!" Yep, you've definetly lost your marbles...
the trick in this game is to get the gyroscopes and then atleast an economic car( better if you can afford it) then go up to a bigger runway so you can get full speed. faster speed at start and more flips = more points. btw dont go straight up for flips, you need distance to.