Honkai: Star Rail stands apart from both Genshin Impact and Zenless Zone Zero in that it’s not an action game. Here’s the official description from HoYoverse.
Zenless Zone Zero, on the other hand, is a fast-paced action game set in an urban fantasy world. HoYoverse said that Honkai: Star Rail is currently hosting another Closed Beta round that began on May 25th, while Zenless Zone Zero just opened up beta signups on the official site and will soon receive details on its Closed Beta schedule. Both games will be released first on PC and mobile, though if Genshin Impact is any indication, they’ll eventually land on consoles as well.