I really don't know what's up with the XP system the reward for playing the game more, is less stuff and I had to go way over what it said I needed to level up to level up.
*Slow clap*
You can use turbo when you're dead and it ends up wasting part of the bar, also these sound effects are terrible but at least you're not asking money for a game as crap as this so you're somewhat better than recent companies.
time your attacks, observe his patterns and try lowering the difficulty a bit.