Dracula is obviously evil, and Simon and crew are always trying to beat up on him. It's not fair. Being evil is always a lot more fun than being "good" - you get to rule people around and maybe even destroy them if they're disagreeing. That is why Kid Dracula is the coolest villain in the universe - he has no hidden agenda, no lust for virgin girls, no desire for material wealth. He just wants to rule the entire world and everyone in it. And you get to control him.
The exact origin of Kid Dracula (as he got called in the USA Gameboy release, and what I'll call him for sake of continuity) is a little unclear. Some people believe him to be the younger version of Alucard from Castlevania III, which i think is silly since Kid obviously has no desire to lay low and help out those wussy Belmonts.
KD wakes up one day from a ten thousand-year snooze. After some refreshing tomato juice (ho ho ho) he sits down in front of his cool bat-style television. Just then, though, one of the castle guard bats comes down and attacks him, swearing allegiance to some dude named Garamoth. After some confusion, Garamoth comes on the TV announcing that he's conquered the world while our man's been sleeping. "From now on," he intones, "you shall be calling me the Great Dark Lord Garamoth!"
This obviously doesn't hold well with Kid Dracula (since he's the Lord of Darkness and Evil and all) so it's time to go on a quest to set things "right" in the world...
The first level is an obvious take on the Castlevania series as it was in 1990 - you got the clock tower, the pendulum which you take a ride on, the outdoor staircase leading up to the boss with the moon in the background, and so forth. The rest of the levels are the same sort of platform cliches you've seen everywhere - ice world, desert world, underwater world, the bit on top of buildings in New York, etc. Nothing particularly new is added to this...
...apart from the ever-present flicker. I can only think of two reasons why this game flickers so much: The people at Konami may have needed their eyesight checked and thought the Famicom looked like a Super Famicom and coded as such, or maybe they had a mega powered up version of the FC that ran on a 65816 and never slowed down. Or something. It's obvious that Konami didn't even try to get around the NES's sprite limits in this game; they decided that big characters were worth the trouble. Some of the coding features are nice (particularly a trip up a cosmic tube via jumping on lots of little platforms) but slowdown can be a problem as well. Good thing emulators don't emulate flicker, huh?
The game's contents are in general pretty fun, and the frustration factor is low. Music is standard Konami; some of it sounds dangerously like polka but there are still one or two good tunes. The manual also lots of important facts about Kid Drac himself (age is 10,009, wears his father's cape, can cavort around in the desert in daytime since no one told him that vampires are susceptible to light and crosses and such).
As long as you don't let the slowdown and flicker tick you off, this is a pretty OK platformer in the style of the late Famicom period. There's a password system up to two levels before the end as well as infinite continues, so this isn't as hard as the other vampire-y games Konami has made. Although I may embellish a wee bit on the importance of this game, it'll give you the quintessential Konami experience, and you can't be unsatisfied with that.
Footnote: Your weapons
After most levels, Kid Dracula is awarded with some kind of new weapon or ability. These new weapons can be accessed by hitting Select to cycle through your choices, and activated by holding down B and releasing. You need these weapons to finish the game safely, so pay attention:
Throughout the game you press B to launch little wussy fireballs which do almost zero damage to anybody beyond the first few levels. Holding down B then releasing gives you this super fireball (1) which is a bit more powerful. After that: