Depending on the definition there are more than a hundred. Find a portrait (ca. 1965) of the first eleven. You will doubtless notice Valentina Tereshkova and should read more about Vladimir Komarov, but unless you truly are a student of manned spaceflight only two names should come to mind: Yuri Gagarin and Alexei Leonov. This movie is Leonov's tale.
I don't view movies like this for their accuracy or dramatic license, while documentaries can only be what they are. (After decades books on the subject only improve on the pertinent tale.) This movie is very well made, paced and acted. (Subtitles never distract me, and it's the first Russian movie I've viewed in quite the while.) Whether you feel compelled to compare it with, say, Apollo 13 or First Man, it is nonetheless another view that you should at least tacitly consent as valid while it strives to entertain, as all movies should but not all manage.
If Leonov comes across as larger than life, the man in real life had every right to be so regarded. He was both a fighter and test pilot AND an artist, and it is no exaggeration to say he was welcomed everywhere. Honor his memory for these reasons as well.
We should also fully keep in mind that when Out There becomes Our Big Backyard (as apparently planned) we should not remember the names of Elon Musk or Jeff Bezos for leading the way but learn and remember the names and backgrounds of, and perhaps emulate, the human travelers who challenge, explore, discover and survive while facing the very great risk of not returning. That risk shall ever be so.
(As for books, I highly recommend those of the Outward Odyssey: A People's History of Spaceflight series published by the University of Nebraska Press.)
