I have also just finished a Kirby game - in fact, it was "Kirby Super Star"
Is it better than "Kirby's Adventure"? Yes. Is it more fun? Iiiii am not sure (pls don't kill me x))
It's definitely more refined than NES title: music (Dedede finally has his theme!), visuals, style (Kirby gets a hat when he is powered :D) and more complex gameplay. And now getting rid of "equipped" power summons a friend :) which is more interesting!
But there were also moments that weren't present in "Kirby's Adventure" or, at least, weren't so obvious that made overall experience not this fun for me
First of all, I am not a big fun of "8 games in 1" format ":D Idk, in this case I would prefer to eat a cake than cookies, like in "Adventure"
Secondly, I am not sold on allies yet. I like the idea as, personally, Kirby without powers is so much stronger, and if I get a friend for not using powers, I won't mind! However, they are a bit janky - sometimes they break my camera, sometimes they destroy projectiles that I need to absorb to fight. And the last thing is definitely a problem in "Revenge of Meta Knight" when there is a time limit and they never do a lot of damage. God, this time limit was so annoying x) I like to take my time with Kirby levels, okay? (but it does work on an atmosphere - God, these dialogues were great)
Thirdly, I don't like to take my time with levels THAT MUCH! For some reason they decided to include these weird puzzle rooms/areas that reset you when you make a mistake. Like, one aquatic level where if you go in the wrong way, even on accident, the stream will push you to the door and you'll appear right at the beginning. It's not like it was horrible - but "Adventure" was so tight with it's gameplay that these kind of boring levels seem out of place
But at the same time, I can't say that "Super Star" is worse than "Adventure". To conclude, I think this game just has some incredible heights (music, scenes, SOME of the boss fights, etc.) but also some lows that "Adventure" didn't have. I'll give the game another shot with "Super Star Ultra" :)