Very simple and just too easy if you mash z and x. Getting to 999 takes about a min or two and there's not much else to it. The art style is nice and the audio is good though the SFX are a bit too loud for the music.
With this type of gameplay, it would be great if after a "run" through a group of enemies your score was a health meter that you then used when fighting an end of stage boss.
Khampret is such a fabulous vampire. I don't get why people want you dead :)