Stephen Georg’s review published on Letterboxd :
For its time, 300 was an incredible technological feat, being filmed mostly (or entirely?) on a soundstage. It's still impressive today, as you watch a group of 300 spartan soldiers perform kill after kill, while they move in both slow and fast motion, to a heavy metal soundtrack.
The film is ridiculous and over-the-top, and plays out like a comic book (which makes sense, since it's based on a comic book). It's pretty shallow on plot—"Persians are coming, let's kill them"—but it does have its moments.
It looks the part of the comic book as well, with dramatic coloring (shadows are crunched to oblivion), and blood spatters that spray in comic-like fashion with every kill. Unfortunately it occurred to me about halfway through the film that, despite the immense amount of blood pouring from the enemies, there was never any left on the ground. It was one of those "can't unsee" things that bothered me for the rest of the movie.
300 is an obvious action film, and does the genre proud. In fact, if you're into this specific theme (soldiers in ancient times), I doubt you'll find a better action film than this one to represent it. Over-the-top works well for action films, and this one doesn't disappoint.
Overall, though, I'm just not that into it. I don't think the movie is terrible, but it's not really my cup of tea. If I'm going to go the action route, I'd much rather watch something like Die Hard and hear John McClane be a smartass. I guess I'm attracted more to the wise-cracking invincible hero than the noble invincible hero.