This is an absolute masterpiece of fanfic if I have anything to say first.
Writing Quality: Perfect, I can count with one hand the typos I saw in thirty-ish chapters. Excellent delivery and proper use of synonymous.
Stability of Updates: Great as well.
Story Development: Naruto came to Marvel to change EVERYTHING, don't spect most things to happen like the original, I love that.
Character Design: Naruto is still an experienced, funny and genius Ninja. Marvel characters are also well portrayed.
World Background: Totally loyal to MCU to the spec of dust.
Now, my opinion:
Dude, author, fam... The moment I started reading it I knew it was from fanfiction.net you only get this much quality from there. Really if most good authors of that site posted their works in this site... They would topple over the ranking in a day.
I have nothing to say about this masterpiece, I only read 30 chapters and I absolutely love it, the way you describe the scenario, the suspense, tension building between characters, Naruto and Nat have a lot of chemistry, that first date lol, very Naruto kind of thing to do.
I'm very expectant about the future of this novel, it says 'Harem', I love harems but just this 30 chapters made me want it to be just Natasha, but well I'm open to possibilities as long as proper drama is introduced (Don't make Natasha just accept it as if it is the most natural thing) and as long as it doesn't go to more than two or three.
I also love the way Naruto handles everything, what a perfect way of using his clones and Hiraishin, his shinobi way of handling himself makes everything more interesting than most fanfic when he just transforms and gets it done. It makes tension to know how everyone will react when he could have just transformed and finished everything yet he only played the ninja around with them.
This fanfic deserves top 10, U gettin' my stones from now on.