Automatic song-rating system.

Album-centered navigation. (e.g. jump two albums down, jump to last album)

Random mode plays high-rated songs more often.

Random queue mode - a list of random tracks you can edit.

Vi-like one-key commands.

Keyboard shortcuts can be easily changed.

Find track by filename.

Build playlists on the fly based on specified score threshold.

Random directory mode plays high-scored directories more often.

Add directories recursively.

Terminal color support.

Command-line interface (no GUI).

You can manually set song scores.

No mouse - full keyboard control.

It's possible to control player externally e.g. by creating window-manager shortcuts.