You can put the Mac to sleep by holding the Play button for a few seconds. A message will be shown when the Mac is going to sleep. And you can wake up the Mac by pressing any button on the remote control.

You can even shutdown the Mac with a little Applescript. Open Sofa Control Preferences and add a new Application. Give it the name “System” for example.
Than add the following script in the editor that shall be executed when the Play button is pressed.

tell application “Finder” to shut down

Press Command-S to save the changes.
The Finder Icon will show up next to the name. You can drag another image there to replace it.

With that in place you can now select this new app with the application switcher and by pressing the Play button you can shutdown the mac.

Unfortunatly there is no way to turn on the Mac with the remote control.