To prove who is the boss, all you gotta do is, toss.
All you have to do is put the coins in the glass by tossing them with the right amount of pressure.
Use the mouse pointer to get the correct angle of projection.
You have 60 seconds to put as many coins as you can into the glass. Go on... concentrate!!
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.