I liked the art style and the idea of using the distance to the objective as a second countdown (I think it fits the countdown theme better than just having a clock).
As another comment mentioned, I also liked that in the third mission you can just simply throw the oxygen cylinders down the mountain. It think it was fuc because it felt like a bit of unintentional comedy in an otherwise serious game. That said, I think it would have been even funnier if the cylinders exploded after being thrown.
I also ran into an issue where the game would sometimes freeze about 1 second. My guess is that is has something to do with loading the cylinders and the physic simulation, but it wans't a major problem.
The only real criticism I have is that the gameplay started to feel a bit repetitive by the end of the third mission, I was still curious to see how the story ended, but I wasn't very motivated to keep playing just for the gameplay. On the other hand, I liked that the tird mission was the final one, it felt like the game knew when to end (But probably was just a thing about the Jam scope or something, idk).
And one small detail, I think it would have been a nice touch if, after picking up a cylinder, the distance marker pointed toward the rover instead. It's not something I actually needed, but I think it would have been a nice touch.
Overall, I enjoyed the game. I just would have liked to see the mechanics explored a bit more to keep the gameplay feeling fresh.
Edit: grammatical errors