My two young kids and I as an adult, love this game overall however a few issues to keep in mind before purchasing:
1) Two players can play at the same time however only one player is the leader and the other is the follower. The former can do everything but the follower can only do limited things like pick up items (I think that is the only thing they can do) For two young kids who both want to play, it's tough to moderate them with this limitation.
2) Also found out their younger cousins have switch and animal crossing, they could not visit our island while both of my kids were playing! (scenario above) so I had to switch users and only let one of my kids play so their cousin could visit. My other kid felt extremely left out. Their cousin was able to do everything but two players in my household can't log in? Shame!
3) I had to upgrade my individual Nintendo online account membership to family so all of my kids can dream into others islands (Before the upgrade, I was the only one who could dream). Aside from what I felt was a money grab, it wasn't transparent that I had to upgrade at first. Initially I thought I did something wrong with my settings as my kids are indicated as 'supervised' in my Nintendo account. I felt it should have been more transparent on what I needed to do.
4) Lastly, I think there should be more tips around the island to help kids get the most out of the game. For example, a warning of some sort that if you use the ax on the tree, it will not grow back! I find I have to watch a lot of youtube video's on what to do next or what not to do like the tree example above. More detailed tips and pointers should something Mr Nook and the rest of the island dwellers should provide. They provide little tips here and there but it's extremely vague. If you don't want youtube videos, I can see players getting bored or just don't play because they simply do not know what to do