the way to get high score is farming on lvl 1 and lvl 2, after found keys just do not go to the vehicle and farm, farm, farm,
but it is realy boring, lol for farming 2,000,000 points its sad.
There is nothing to do with skill points gained above 42lvl, You should make something with it. Points should be used for improve speed attack, dmg, and range.
this game need power different jumps, not only one kind of jump. It also need progress taskbar or something to know where are you on current playing lvl.