One of 593 to get impossible badge. Feels great. Here's some tips.
You want to try and keep your combo up. At low levels that means getting every enemy possible. Later on as it speeds up you want to take the ones that are not going to cause you to get hit, losing the combo. You want to stay up in about 1/5th of the screen I found out after getting 50 grand and decided to go ham. You're able to move back if you have your fingers warm and most enemies will die if you slide forward and attack. Then move back. Other than that I would kill most enemies by jumping and then ground pounding. Try and figure out which enemies are not worth the risk of trying to get and in what spots. Try and get as many flowers as possible. :)
 "Rogue Soul 2"){kind=icon}
 "Tyrant"){kind=icon}
 "Depict1"){kind=icon}
 "The Tickler"){kind=icon}
 "Dungeon Defender"){kind=icon}
 "The Enchanted Cave"){kind=icon}
 "Boxhead: The Zombie Wars"){kind=icon}