Well I only played Pikmin 2 before this and it was when I was a teen. At the time I didn't finish it because I got intimidated by the mid to late game difficulty.

The way Pikmin 4 introduced elements over time it felt like a new start. The first credit roll wasn't too hard to reach and now I feel like I might end up committing myself to 100%ing the game.

Also Oatchi. Oatchi is everything. I think it will be hard to go back to playing without the dog because it is so convenient. You can carry your Piks over obstacles, he can be an initiator tank in a fight, and you can divide and conquer by sending him to another location to guard or dig up treasure while you and your Piks do the work elsewhere. Plus he comes back to you on his own. He's a good boy.