The biggest cultural phenomenon. I have yet to play it in actuality. I’ve started up a couple worlds between my home computer (set up as a server) and on my steam deck. It’s compelling enough for someone getting into the crafting/survival genre of games. As far as objectionably material, I’ve yet to find anything, however, there is a very large modding scene, so depending on if you are playing on PC or Mobile, modding is something to monitor when considering your children.
It also has a strong online presence, encouraging you to play with friends over the internet. As someone who played Halo Reach back in the Xbox 360 era, trust me when I say you gotta be careful about who you play with online. Online play can be a mixed bag when it comes to people you meet. The rise of services like Discord replacing in game chat for most online games have largely self-filtered out most of the negative experiences you might encounter when playing games online, but you as a parent should still monitor who your kids are interacting with by asking about names, stories, and concerns they might have about things people may have said.
As far as ages, you can probably let them play as long as they can manage controlling a first person perspective, either with a controller or mouse and keyboard.