Thanks for hosting the jam and the great feedback! The yellow bar is for something I didn't have time to implement. I guess I'll keep that a secret. There is a boss fight, and yeah it's a pretty big map to explore, but hopefully you found the weapon powerup which allows the traversal of more of the map.
Things I would like to add: proper story dialog, some environmental differences to break up the size of the space station and support the story, and the yellow bar stuff!