Well, I’ve played a bunch of Honkai Star Rail. tl;dr: Cute game, terrible leveling system.

I played some of their earlier big hit, Genshin Impact, which has the same cute anime characters, element-based combat, and gacha system, but is more of an open world. I kind of lost interest in it, but not because I ran into any barriers.
The pressing question is of course, what’s a Honkai? It’s 崩坏, which is Bēnghuài… for some reason Mihoyo, a Shanghai studio, likes to name its games for the West in Japanese. It means “collapse” or “breakdown.” Apparently the first Honkai game was a zombie shooter, while the previous one, Honkai Impact, is “post-apocalyptic.”
The Star Rail is pretty literal: there’s a train that goes around in space, you see, and you join its crew. That’s maybe the first clue that this is not hard sf. Also there are godlike beings called Aeons– one of them created the train. And things called Stellarons cause trouble for humans, which the crew is supposed to solve. All this of course gives you, the “Trailblazer”, an excuse to visit various planets, explore, and fight monsters.
There’s an introductory section on a space station where you wake up with Plot-Based Amnesia, and which is suffering a monster attack. You clean that up and then go to a planet named Jarilo VI, which is heavily based on Russia… pre-Revolution, apparently, as it’s divided into an aristocratic Overworld and a mining-based, oppressed Underworld.
The fighting is turn-based, which is awfully reminiscent of the 1990s, but hey, I liked the King’s Bounty games, and at least there’s no twitch mechanics. Different enemies have weaknesses against certain elements, and each of your characters specializes in one of those, so you want to pick the right team for the right enemy. It’s pretty satisfying if you can arrange the fight so the enemy doesn’t even get a turn. The four-character teams also make more sense here than in Genshin Impact since you see all four of them during combat.
I might add, don’t get this if you’re impatient. Turns take awhile, especially because your ultimates (which you will get several times per fight, for each character) each have a pretty long animation. (They’re also so bright that they hurt my eyes.)
Now, when I say you’d better get the team comp right, you’d better get the team comp right. Twice I ran into enemies (Svarog, then Gepard) who defeated me multiple times. Both have huge health bars and you absolutely need the characters that hit their weaknesses. If you lose a fight, the game will tell you the monster level, and if it says you’re too low, you probably are, and had better grind a bit.
Interspersed with the fights are little story missions. One charming bit is that your friends will send you text messages, often weird and baffling ones.
As you may expect, the major gotcha in this game is gacha. I haven’t had to buy anything, but to motivate buying things they’ve made the leveling system arcane and annoying. There is a plethora of special currencies or leveling-up items… separate ones for your own “Trailblazing Level”, your characters, and their “light cones” (repositories of extra stats). You can get completely blocked if you run out of one item or another, perhaps for just one character.
For the most part, there are ways to get to level 40, at least. I had to do pretty much every side mission. Plus, there are Golden Calyxes, little fights you can get into a limited number of times a day, but which reward you generously with the McGuffins you need to level up characters.
But now I’m stuck. You see, the next story quest has a level 42 monster that I can’t defeat. And there is literally no way to advance past level 40. You can’t just grind, you need to pass a certain story mission… one that’s after the quest I’m on. I can’t even buy stuff to advance, as it’s not gated to materials but to the story. This doesn’t seem intentional, or sane, so I filed a bug report, but for now at least there’s no use playing more.
(Also: in a normal game this would be fixable by turning the difficulty level down. But of course they won’t want you to be able to do that in a gacha game. So even though I can’t fix the problem by spending money, I’m still screwed by it being a gacha game.)
Edit: I got unstuck. First, some tweaks to my characters (leveling up all the accoutrements for everyone), I was able to beat Mr. Level 42. Second, it turns out that monster wasn’t necessary for the mission– it was only guarding a special chest. So I was able to move on, and even defeat Cocolia on the first try. Jarilo-VI saved, though for some reason there are a bunch of quests added after the main mission.