Thank the heavens you probably haven't played it
Graphically, the game is sound. The sprites are large, the backgrounds are well detailed and movement is mostly fluid.It takes more than good graphics to make a good game, however, and Master Karateka fails in every other field.
It plays a lot like Kung Fu on the NES, albeit slower. A lot slower. At the start of the game you can distribute skill points to tweak your character in the areas of Power, Life and Speed. No matter how many points you put on the Speed attribute, your character will still move like his feet are made of concrete. You can switch to running, but do this and you'll almost certainly run straight into an enemy's attack.
I haven't got a clue what the plot in this game is. You're shown a bunch of dialogue-free cutscenes, but all this shows is that the bad guy (whoever he is) has a fetish for masks and likes to point a lot. You'll wander from one side of the screen to the other while facing off against these generic bad guys who'll do nothing more than punch, kick, block and occasionally throw things. You can take them down by also punching and kicking. It sounds easy, but it really isn't. As I mentioned before, gameplay is slooooooooooow. Not only does your character have concrete legs, but he has concrete fists as well. There is no real variation in the enemies and their fighting style. Everyone you encounter seems to be the same mask-wearing karate guy or harder(and by harder I mean insanely overpowered) boss masked karate guy.
The game is very difficult. Even with the tweaking of skills, it is still unforgiving in his difficulty. Put all your points in speed and you won't encounter as many enemies but you'll probably be taken down by the first guy you see. If you put it all in power, you'll take down enemies easier, but there'll be whole lot more of them to take care of.
The soundtrack is unremarkable. While games like Link's Awakening and Kirby's Dreamland proved that you could have a good soundtrack with the Game Boy's limited hardware, Master Karateka fails to rise to more than standard bloops and bleeps. The music is supposed to sound tense as you approach an enemy, but seeing as it's only two bars repeated over and over, it creates a feeling of irritation more than tension.
The one good thing this game has is the ability to skip levels, because you probably won't want to sit through one long session of this snooze-fest. Either that, or the developers couldn't be bothered implementing a password system. Regardless, you probably won't want to sit through playing any of this game. It is a monotonous, unenjoyable, concrete limbed game, which deserves to be doomed to obscurity.