Even though I have the speed-increasing upgrade (in fact, I have every upgrade), the dragon in Zelbos Pass moves faster than me and always catches up and kills me before I reach the first pitfall. Sliding doesn't make me move faster, and attacking the dragon doesn't slow it down. The newly-introduced bear-traps also only hurt me and not the dragon. Am I missing something, or did you mess up the coding in the latest Windows build?
EDIT: Also, please reduce the health of all the bosses; they're all massive damage sponges that take too long to die, especially considering how short their patterns are.