Could be 4.5 stars maybe, even 5 for someone who was more into this kind of thing.
Of course the complicated part there is, what kind of thing is this?
* Debut novel, with the expected overgrowth of random ideas that could be awesome in a separate book.
* Puppy love.
* Magic vs. Technology (the magic system could use a bit more detail, the tech system, if that is even a thing could also (where did the 2 second time machines schematics come from?)
* Lovely writing
Did I mention that Technology here feels more like a separate school of magic than what we IRL understand as technology? In some other book (Wearing the cape, maybe?) I read about a sort of superheros/supervillains called "Verne" who were able to create random "technological" gizmos and materials that despite looking science-based were in fact totally impossible for normal people to reproduce. That's how some of the "tech" things in this book appear to work, and I think it makes the book slightly more interesting to me: it's a book about a war between two magical factions, where one of the factions doesn't know what they do is magic.
All in all, very solid, entertaining book.