Echoing Darkness

You are a diver that can only face up, so you need to use a sonar gun to reveal your environment -and see through the darkness released from a mysterious entity. You must swim away from a beast that will chase you through perilous traps and puzzles until it corners you at last. How will you escape to freedom?
Jam Site: 
Jam year: 
Another way in
Lost library card
MS Windows
Tools and Technologies: 
Unity (any product)
Game Stills: