I bought Pikmin 4 a few weeks ago- but have been waiting to play it until after the Game Jam- I was spending all my time learning how to use Unity, create art, and create music leading up to the Jam. Once I was able to finally sit down and play it- lol all I saw were things they did very good with their dialog system that I would want to implement as well. XD So, here is my list of things I really liked from how Pikmin 4 handles their dialog system:

• When you get close to things like a fan, the main character says things like "Feel that breeze"- but not every time; This is not only immersive but helps draw the player's attention to the fact they can use the fan somehow.
• When the camera was aligned in a way you could not see much, the main character would say things like "I can't see very well; I should use the right stick to move the camera around"- which he ONLY did during the tutorial level; It was a helpful reminder for my 6-year-old daughter that she needs to pay attention to the camera.
• When you would encounter a mechanic for the first time, a popup would appear with a video on the action being done and some text explaining how to do it; This would be annoying for veteran players or people used to how games work- but it was indispensable for my wife and daughter when they tried it.
• They provided choices in dialog that did not ultimately make a difference, but were still funny (like choosing not to say the right thing when everyone salutes the captain).