You can beat lvl 4 by using the front + attack too. I keep cutting past the demon, and he hits behind me. While he turns and try to attack, I cut past him again.
End up, he keeps turning around and around
Damn, nearly 50M score.
All time number 8!
Rather easy though. If there's autofire for powerups, I'd go higher, since all I did was press left and 1,2,3,4,5,6,7 when I can.
 "Sheepish (JOGO)")
 "Ether War")
 "The Heist")
 "Warlords: Heroes")
 "loops of zen")
 "Mud and Blood 2")
 "Infection")
 "Epic war")
 "Solar Chiefs")
 "Clear Vision Elite")
 "Brute Wars"){kind=icon}
 "Kongai")
 "Pandemic 2")