Arnt you a little old for videogames?
I don't play Karate Champ nowadays.
I played Karate Champ (in the Arcades) back in 1984.
You can never be too old for videogames though, they have evolved quite a bit since the early 80s.
What Karate Champ brought back in the 80s was a very unique player interface not seen before at that time.
It inspired alot of fighting games.
Without it the world would probably never have seen games such as Streetfighter, Hit the Dindu, Kung Fu, Bruised Lee and the like.