Protect the tree from invading spirits by batting them with your tail and breathing fireballs. This is the sequal to Shen Long.
If the game lags, try turning the particles off before setting the quality.
Move with the mouse and shoot fireballs with the left mouse button.
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.