MPlayer.app is a GNUstep port of MPlayerOSX.
MPlayer.app is a front-end/controller for MPlayer, using its --slave API. It is based off MPlayerOSX and contains changes towards building it on GNUstep.
It supports queuing of media-formats supported by MPlayer in a playlist. The playback window it spawns is that of regular MPlayer.
I fixed it up, added some icons for the file-types it ought to support and made the main app icon look like something you'd see on a GNUstep system.