Okay, so something that has been bothering me since re-watching the trailer is the severe lack of the return of online mini-games. Hear me out, and I don't want to sound like a negative Nancy or a pessimist, but here is what is troubling me.
This is baffling to me with Nintendo's messaging. They claim to be "improving" the online play, but their focus is solely on upgrading so that 12 players can play on your island, and yet they don't mention the return on online mini-games.
Moreover, why didn't they show any improvements to online play? You mean to tell me that they are still using that stupid, outdated system where, when someone is coming to your island, you have to stop what you're doing to see them arriving? With 12 players, that is like a nightmare. It takes around 3 minutes for a player to arrive on your island, and when you multiply that by 12, it would take a whopping 36 minutes for every single player to visit your island. You'd better hope and pray one of them doesn't lose their internet connection because that would be a disaster.
They are only doing this because they are focusing more on the Slumber Island concept for the dream island, but we don't know how it will work. Can you host your slumber island and then have a dream address for your friends to join in? How long would it take for them to join in? All these questions, and we still know very little. They have really replaced online mini-games with this Slumber Island sandbox. I am not sure if this is a good thing from now on or a bad thing.
