The key thing to understand is that you'll be taking control of atreus around five or six times during the main story. These sections are pretty interesting actually since they change up the gameplay and show things from a different perspective. You'll first encounter this during that big hunting chapter called hunting for solace, where you really get to experience atreus working through some heavy emotional stuff

The gameplay really shifts when you reach ironwood with angrboda, and later when you make your way into asgard where there's some really tense moments with odin and thor. Something worth noting is that while youre playing as atreus, the combat feels totally different since you're mainly using that bow of his and focusing more on being quick and nimble

Not everyone loves these parts since they can slow things down a bit compared to the intense combat you get with kratos, but they're really important for understanding the whole story especially when it comes to atreus becoming loki. The mask quests in niflheim are particularly interesting, and they tie into some bigger stuff with odin that becomes pretty important later on. If youre wondering when you'll get back to playing as kratos, dont worry too much since these atreus sections are spread out through the story and each one serves its purpose in the bigger picture