You need to bounce the heart moving the bear left and right with the arrow keys, and each bounce advance you a month in the relationship, each year you will have something new to do and you will notice changes in the life of our little bear, if you advance enough you build a house, have kids and send them even to school ...
A context menu should be shown when right-clicking or, on touch devices, long-pressing in the game. This menu especially allows to play in full screen and control the volume.