Alright, here are my impressions I've assembled during my playthrough and a verdict at the end:
Starting the game
I'm playing in classic B/W mode on my trusty purple GBC. Right away I'm reminded of better days (for Konami, anyway) after seeing the dev logo pop up. I like how the seemingly gloomy intro transitions into the cheery music and pose of Kid Drac's big sprite. It sets the tone quite nicely. So does the music and Kid's goofy (anime) visages during the first cutscene. The story is obviously geared towards people who didn't play the NES one (as it's just the same thing happening again, only with Garamoth being "stronger"). I suppose that's why this game is considered a remake of the Famicom original.
Level 1 - The Castle
First of all, man, this game really wants you to keep playing. The 8-bit snoring sound Kid makes when you pause the game is, uh, quite persistent. Thankfully, no time limit means that you don't really have to pause if you wanna look away for a second. Anyway, the game starts off with some jaunty music and some light obstacles. I like the episodic nature of the levels, so to speak. Every screen transition holds news ideas that are iterated upon in various ways. A lot of the locales are obviously reminiscent of Castlevania levels and so is your progression through them which seems to have the same logicality to it, albeit in a slightly "looser" way than CV's castle structures. Kid's animations (dat hair) are really neat to look at without getting in the way of mobility. Shooting up and down is always fun. Furthermore, the size of the sprites is just about perfect for the level architecture they've created.
I quickly figure out how to turn into bat. Applying the same logic to my fireball, I also discover the charge ability which should prove essential. Moving on, I get my first coin drop. Right away I'm faced with the question if I should farm these in an easy spot since there's bound to be a shop at some point but I decide to press ahead.
Moving past the clock tower area, I notice the pictures of Dracula Sr. (Alucard? or would that be me) hanging on the wall.
You leave the castle pretty early and some jazzy tunes welcome you to the starry night. I recognise those tipping platforms from Castlevania 3, although I find them to be less of a challenge here. Time to fight the first boss while the moon is asleep! And.. the boss design sure is a surprise. I already love the humorous element to it. The ending to the fight got a good laugh out of me already.
One cannot easily forgive a traitor, bat! And with that..
Level 2 - The Woods
Oh yeah, I almost forgot. Cute witch lady let me try for "another Kid Dracula" (clones?) for the low, low price of 10 coins so I went for it. Having different bonus games is definitely appreciated. I lost my first game of 'Stick'em'. That game seems fishy! 'Grab Bat' is way better and actually skill-based so I got 3UP out of that. Nice! I played the coin game with the two coins I had left. It was basically roulette so I ain't playing that again!
I'm already getting strong Kirby vibes from this level. The horizontality of it is awesome, and speaking of Kirby, those trees sucking you in are a really creative hazard.
I don't know what the second section is about but it sure is fun! Ducking under owls to win a race between floating corn stalks? Sign me up.
I really like the juxtaposition of having to be patient in the first half of the bridge section and the adrenaline rush in the second half. The latter part seems tricky at first but jumping in advance to meet the fish with charged fireballs makes it a cake walk.
The boss design takes me by surprise and I love it. The expressiveness of the characters also goes a long way. Somehow I nail him on my first try without getting hit, woo! The new Homing Shot seems neat, we'll see if it'll prove useful.
I go for the third minigame this time, 'RPS'. I fail terribly at it.
Level 3 - The Clouds
The first section is fair enough but the real highlight here is the rollercoaster. It's not a short section which contributes to the tension of it all. I love the attention to detail with the direction of the boost flames.
The boss sure takes a lot of hits, though. On the flipside, you can farm the chicks for coins! Homing shot recommended.
Jump & Pop is without a doubt the second best 1UP game (of the two viable ones). I'll be sticking to 'Grab Bat' in the future, though!
Level 4 - The Airship
The first section has this very interesting idea of a rocking ship, influencing your field of view. The second section follows that up with the first 'switch gravity' experiments which are elaborated upon in the subsequent section.
The first form in the boss is easily caught in your homing missiles. If you spam them at the right speed, he doesn't get one attack in. I suspect this is the case with a lot of bosses in this game, certainly with the Chicken from the previous level. The second form took me by surprise but considering the gimmick of the level, it didn't take me long to figure out how to take that guy down. staying close helps!
Before taking on the fifth level, you are treated to another cutscene which grants you a new item (on top of the usual new ability which is the Bomb this time) - an umbrella! Useful for blocking projectiles and also comes with some neat spritework of Kid Drac hiding under it!
Level 5 - Space Elevator
A short one but a good one. The first section is a pretty exciting horizontally auto-scrolling jumping section, followed by a short UFO-filled interlude and.. Mecha-Garamoth. A challenging fight at first but no biggie, once you get into the rhythm of it. Figuring out how to hurt the second form is tricky, even though it's kinda obvious when you pay attention. You just get a short window and small hitbox to get your hit in.
The real highlight is me getting 7up in one round of 'Grab Bat', though. Nailed it.
Level 6 - The Volcano
Another short but intense stage. I especially like the visual design in the first section and the volcano element in the second section. It straight-up feels like you're playing through a Gradius level, only it's a platformer. Really cool. The boss requires some basic pattern recognition, I guess a second form wouldn't have hurt it. Also, it looks like a Pokemon.
Level 7 - The Mines
Definitely the level I feel most ambivalent about. While the necessity of precise bomb employment and quick timing is appreciated from a challenge standpoint, you get crushed really easily between moving blocks and digging your way back is straining (mostly on the hand).
However, the boss fight is fantastic and probably my favourite in the entire game. RIP Spark Man.
Level 8 - The Robot Factory
The final level definitely kicks things off with a rad tune. And proceeds by punching in the face repeatedly. The first two sections require some real detective work as you figure out which path leads to the exit. The first time while being faced with a level that is continually scrolling down while you have to make your way to the right (which is something you have to figure out first, mind), while the second has you going up and avoiding spikes. Quite a jump in difficulty compared to what the player has been pitted against so far. I haven't done this comparison for all the levels but the second section is definitely an instance of US/EU players getting way, WAY less hearts than the JP players. Quite an unusual case in those days to have a Western version that's less forgiving.
The third section is filled with traps. It's definitely quite devious and you have to proceed with a lot of caution (or just know about the surprises beforehand by dying to them in an earlier run). The rest of the level is fairly forgiving but the final boss requires some strong nerves. After I had the first part down pat, I tried to focus on the second part and eventually figured out the timing to hitting him without getting hit myself.
After more or less cruising through the rest of the game, the final level took me several hours to beat. Needless to say, it felt rewarding as heck (even though the ending is utterly unremarkable).
I also found out afterwards that there are heart containers that I missed. I only got the one in the final level so I only had three hearts for the rest of the game (and four for the final boss). I'm sure it would be less stressful if one approached the final stretch with a total of six hearts.
Closing thoughts
Kid Dracula is clearly one of the best platformers on the system. The game shines in pretty much every aspect. The level design is varied and creative, the soundtrack is consistently great and easily one of the most sophisticated on the system, the shop mechanic is relatively well implemented, the way new abilities are introduced is exemplary. A stand-out for me are the bosses which keep things fresh and are rather memorable and often wacky. As is the entire game, really - try putting in the Konami code, for instance! It's a shame the series pretty much died after this entry.