in the second fight of 0-1, only use a double down kick for the right one, and then a high kick for the left one

in the third fight of 0-1, do a double down kick with the first down kick on the black jar for the bottom two enemies

in 0-2 it's slightly faster to power attack ASM across the gap before starting the fight and then doing a double down kick on the enemy

in the second fight of 0-2 do the same thing except when on the other side use 4 bullets from a fully upgraded gun

in the last fight of 0-2:

1. take the RPG7 and shoot a rocket to the left and the right
2. switch to the modern rifle, shoot two bullets to the right and two to the left
3. drop down, defeat the three enemies with 5 bullets from the modern rifle
4. exit

in 0-3, ONLY ever try for a double down kick on the shielded goon, if they block it go to the vulnerable side and do the same thing