Tsuki Adventure is the very definition of an idle game. It's not just you who's idling either, because the rabbity titular character is taking things nice and slow too. Essentially he quits his job and heads off to live a live of quiet relaxation in the countryside. He's supposed to be running a carrot farm, but that basically takes care of itself.
You'll buy Tsuki little gifts using those carrots, and then he'll have little adventures. Buy him a fishing rod and one day you might find him at the water's edge trying to catch something. Buy him a skipping rope and you may happen upon him having a little play in his garden. But you might not. Tsuki does what he wants, when he wants. And the more gifts he has, the more options of things not to do he has.
It's not the sort of game that's going to steal your existence, but you will probably pop in every now and then to see how Tsuki is doing. He's not a virtual pet, he doesn't need your love or poop-cleaning skills, but he'd love to hang out with you for a bit if you're free.
Tsuki is basically the sort of friend who is a rabbit that we all want in our lives - one you don't really have to do anything with who doesn't mind that. If you'd like to install him on your iOS device then click here to grab it from the App Store. If you're a gamer of the google persuasion though, click right here to pick it up from the Google Play Store.