hold middle mouse button (or left+right at once if you have middle-mousebutton-emulation) and move your mouse to move around the world

hold right mouse button and move mouse to rotate the mouse (look around)

left mouse button is for clicking :)

press f2 to get in ego-shooter mode :D you can use w,a,s,d for movement now. f2 again to deactivate. this only works with dot_mcp, the others above work out-of-the box within the server.