Took me a minute to understand what I needed to do but a quick read of your submissions got me on the right track!
Ok! Game has a great atmospheric vibe. The wonders of space or of the ocean are always such a vibe. Great SFX, intro music, and feeling of vastness. The low poly art style and modeling and texturing are great. I like the fogginess of the scene and collecting the shells to replenish oxygen is a good mechanic. I never got all the barrels, because I kept dying pretty sure my pathing was incorrect to keep my O2 levels up. Overall I think this is an unique submission and really enjoyed my time in this world.
Great job!