Definitely this, I had the most fun learning about the new stuff when I came back in Dec 2016 after a 2+ year long quit. It was refreshing and exciting.
I made long term goals like trying to acquire all the whites, finally get white star and earning 100k fame. It got me occupied for 6-7 months, but alas, my interest in this game has died down because I decided that taking down cat dictators with a scrawny plane was more fun than this.
I’ve accomplished much, reaching 90k fame and getting every non-limited-time white except for Shaitan’s 2 whites, Thicket’s last white, and recurring terror. I’m pretty satisfied, so if I do take a break now, it’s no loss and I’m happy :>