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