You can control the player in four different ways:

a) clicking the buttons ;)
b) popup menu on rightclick
c) keyboard shortcuts
d) systray controls (depends to systray configuration)

Ad a): Try all combinations on each button (left/right click, doubleclick, click&drag, ...)

Ad b): The popup menu might not work an some designs, since it's fully customizable in the design. Try to right-click on other places on the player...

Ad c): All the shortcuts are listed in the popup menu. Note that the shortcuts are also customizable in design, so they might differ in some designs. Here' s the default shortcuts list:

General:

Play:

Miscellaneous:

Ad d): The systray controls are fully customizable. You can use up to 9 icons for Pulse control in systray, define left button, right button and doubleclick action and toggle taskbar item.