(I am now in a rush to test as many games as possible to help, so please do not mind the cursory reviewing style.)

Semi-on-the-fly remarks:

(silly detail) The icon for the executable is too cute. X) :)

many options for the graphics, nice (although this is probably somewhat bundled with Unity?)

Some sounds for the dialogues (when a character writes, or when going to the next line) could be nice, but this is really a detail.

(another silly detail) "Alex": as a coincidence, I played a game where the hero has a (poor) friend (?) named Alex, last night. X) "Love Locked"

controls ARE layout-independent!! :D (I have an AZERTY keyboard) Great. Anyway, the arrow keys are enabled too, but this is still potentially handy.

Wow, great scenery! Both the environment and the artificial structures.

great that the interface reminds you of the collecting key!

Low gravity jumps, great. :) … But wait, isn’t gravity HIGHER on Mars than on Earth? :o Nothing serious, though. X)

great indicators for localising objectives! (direction + distance)

Oh wait, the controls are NOT layout-independent for the VEHICLE!! :o On my AZERTY, going forward should be Z, but it is W! Thus using the arrow keys.

The vehicle physics is fun to try out. Feels like a hovering truck!

Leaving the vehicle on the fly reminds me of "Unreal Tournament 2004" X) (Soon after the beginning of my second try: I realize ‘unstucking’ vehicles is ALSO in this game!)

Moving the camera zoom with the mouse while onboard is so intuitive I almost did not take note of the comfort, well done :)

Spoiler: just before collecting last rock sample: oh, so THIS is one of the shadows, sideways behind a big rock! So, the icon I thought was cute is in fact semi-creepy and evil XD

Not trying to see what happens when you go to the borders of the map, since it looks far visually and according to other comments, but I wonder if you made sure no bug would occur.

[gave the samples]

Haha, funny dialogue about where we found the rocks. XD

I think the absence of music is a right choice for the atmosphere; loneliness, mystery, and exploration. ("The Witness" does the same.)

Oh, sunset? Oooooh, you see the Sun move in real time!!! :D Great! Makes me think of "Ocarina of Time".

Nice, automatically leaving the vehicle (near the drone) with a line of dialogue. (Ah, actually, merely a required crossing point! Still, nice dramatisation/narration.)

Oh, graphical bug/limitation: from the place where you leave the vehicule, looking at the giant vertical rock only shows part of it, because it is too far from your line of sight. (Understandable, seeing the graphical quality and the relative flatness of the big map, so I am not complaining.)

Crater: not wanting to spoil it, but the dramatisation is just GREAT! XD Both funny and spooky/eerie at the same time. :)

Leaving the crater: I do not know if this is on purpose or a coincidence, but the shadow (from the Sun going down) covering and bathing the place as I run, this feels great, as an ominous omen. XD

Definitely looks like the general shadow moves according to us, so this is entirely voluntary. Well done. :)

Not allowed to go back onboard, so trying the U key; oh, makes the vehicle suddenly disappear!! <:o I hope it teleported to some nice place and this is not a gamebreaking bug… Oh, it’s all dark! And the vehicle is back, falling from above; frightened me!! XD

Spoiler: steps behind me? Yes! Not turning back… OH, NO!! Was there any way to figure out how not to get caught?! ._.

WHAT?! Are you telling me I have to start all over again from the very beginning?? <:o Oh, no… I feel this is really a BIG problem, because accomplished the preliminary tasks take way too long. You definitely NEED to add CHECKPOINTS. My God, I am really trying hard to be less slow of a reviewer, and this happens. XD

Small bug: pressing Escape during the dialogue then trigger the pause menu after the dialogue, but you can see that the view is moving, so not really paused. (by the way, makes me realize that vision moves a bit when not walking; nice detail!)

Wait, I realize I do not hear my steps anymore in the second try! :o Audio bug? No more sound? But I will need it against the shadows!! :o (Spoiler: my intuition is that I should have looked at the shadow to make it go away, but I am unsure. So, I need to hear the steps.)

Oh no, gamebreaking bug: if you inspect the drone from a bit too much sideways, changing orientation apparently does not trigger the rest of the events, and you are stuck there without any walking allowed!! <:o

Stopping my test here is more reasonable…

I am VERY curious to know what the gameplay with the shadows is. So, could you please tell me more so that I get a better idea of the rest of the game? My judgment will reflect this, I do not want to be unfair to the game! Although I rather like what I saw up to this point. :)

Takeaway: great idea, great atmosphere (especially the choice for the smiling shadows!! Same phenomenon as people afraid of clowns, I guess XD), a lot of subtle interface/ergonomic details. My main criticisms would be that distances are a bit long (as others said), the lack of a checkpoint/saving feature (highly needed here, especially considering the previous point!!), and perhaps a lack of clarity (! Pun not intended XD) about how to deal with the shadows — although it may be your will to let the player figure it out, but then again, in this case, see point 2: checkpoints.

I enjoy those Mars exploration games and this one is no exception. :) Just still curious about what the gameplay has to offer. Thanks!

Impressive work for one week, even if you used some assets. Those rocks are true beauties.

Even when using the vehicle (and its availability also is pretty impressive), the area is too big. Well maybe not to big but too empty to catch interest for people in the jam. In my first try I walked to the crater by foot and it was quite boring.

I liked it, the only thing I would say was that the vehicle movement was a bit strange and it was difficult to go in one direction 

The landscape and the floating vehicle is nice.

game involves lots of walking, and the move speed is so slow making the walk feel boring. The environment is  nice, but the atmosphere doesn't feel like mars atmosphere. Only saw the shadows once. Good job though!