The artwork for Tsuki is beautiful. Cell shaded foregrounds, with beautifully rendered backgrounds. As the time changes from day to night the scenery will light up, moon rise, and shops close. The other creatures are interesting, some of them with stories to share with you. You can send your little rabbit friend out to use some of the items he can buy at the shop, like the kite, and the fishing pole.
Each day the diary will gain new entries. The carrots will grow and you can have the little rabbit gather them up. Carrots are used to buy things, and you can sometimes get fertilizer to make the carrot grow HUGE!
Once you gain enough carrots you can buy a ticket to the city and explore the night life. There are more characters to meet, and the shops in the city have different items. And there are rumors of another place you can go, a mountain pass only available after purchasing the right item. There he can climb a rock wall, get lost in the forest, and find runes.
You unlock different areas and activities by buying certain things from the shop. Also some activities are only available at certain times of day. Unlocking some may make it possible to find others, as well.
The advertising in the game is optional. It will give you more carrots, but you can always tell the game you’re not interested. Otherwise just check in with Tsuki every now and then to see what he’s doing, and get him more things to interact with to grow your memories.
For more information on how to trigger certain events try the Tsuki Wiki.