By passing in True when I created the MediaPlayerBox, that told it to display controls. You can also control whether controls are displayed by setting the controls_visible property:
self.player = MediaPlayerBox(True)
self.player.uri = file_to_play
It's got other functions that you would expect:
self.player.controls_visible = True
And other useful properties too. For example, you can get the duration of the current media file, and you can get and set the current position. So you could seek to halfway through the media file like this:
MediaPlayerBox is really just a thin wrapper around the gstreamer's playbin, so you still have all the power of gstreamer if you end up needing to go there. You can just use the playbin property and go to town if it comes to it.
dur = self.player.duration
self.player.position = dur/2
But MediaPlayerBox is focused on simplicity, just getting a video or song playing n your app esasily.
MediaPlayerBox is currently in a branch, so you can grab it and try it out.