Here is the full list of all 18 Karate Master 2 Knock Down Blow achievements.
Defeat Oboro.
Defeat the bear.
Requires toughness 10
You need to earn 1500 bucks.
Requires KI 10
Requires tai kitae 10
Win the Kumite tournament.
Requires speed 10
Defeat the bull.
Jump over a car.
Defeat the legendary Sensei Matsu.
Reach fame 100.
Win a Karate-Pro tournament.
Win a ring event.
Requires strength 10
Win a Bogu Kumite Tournament.
Heal yourself in the hospital.
Win a Full Contact Karate tournament.