To be absolutely honest, this is an amazing start for a game, I only say start because it obviously has a lot more to add but this is a great start and impressively so. Now, just as suggestions, you should create a discord specifically for this game, to make suggestions, bug reports, and just a community in. My second suggestion is of course the save system (which I see your working on). Increase the biodiversity in the game a little bit, while remaining still all about being in a desert. (Add caves, maybe underground rivers and waterfalls). Maybe add certain animals that live in the caves and maybe some hostile ones that pose a challenge to the player so it forces them to be quicker, adding a survival aspect. You should add a difficulty setting that gives players the option to choose how hard it is to get resources, how hard the entities that fight back are. A lot later in development you should definitely add a price tag onto this game and maybe think about CO-OP playing. But this game is an amazing start! I am gonna add a list just in case you choose to take these suggestions into account with a few extra. I do understand though that you might not want to turn this into a full scale game project, but this is good shit in the building/survival (astroneer/subnautica/forest type stuff) game series. I suggest going full force, it could really be a hit.
-Change the walking mechanism to not lag and make you walk further then you go
-Add a saving system
-Make the quit button usable
-Add a settings menu to change sound (and other things such as graphics later on)
-Add a moon (lol)
-Make it so your mouse does not appear when clicking in a GUI
-Add a clear GUI in the research table how to research, like say if when you get tech points but researching again and again, it increases the efficiency of the things you researched, if its just there for multi purpose aesthetic. (Basically like what each research does, just add a desc and a percentage it increases by)
-Add a description for each building and what each building does
-There is a battery capacity Tech upgrade, then a battery capacity normal upgrade, remove one or if there both meant to be there then just give a desc on each.
-Have an interface with water, health, food, (if you choose to go survival route) time, and it show what building your looking at or ore.
-Fix some terrain generation such as the photo I have replied to myself in the comments with.
-Have a research that upgrades ability to sell.
-Interface on drill to let the player know how much material it has left to mine(In later suggestions), and what material it is.
-Add an actual mining storage
-Make it so you can continue playing even if you do win (the save file)
-Add a difficulty system
-Create a discord
-Add a character model
-Increase a certain level of fog at night
-Make a temperature system where it matters if you are in your house at night or not.
-Increase the sand to look a little lighter and more detailed.
-Ability to flip buildings around and edit there placement.
-Ability to connect certain buildings
-Give the corporation you're sending all these materials to a name. (Like Jevil_FromVSauce Corp) [hehe]
-Add a variety of music! Maybe even some for different situations (Like an entity attacking or sound effects for caves)
-Add an ability to destroy buildings
-For research: Make it so after a certain amount of upgrading something it gets some sort of big upgrade or ability (Like the solar panel working at night at a highly lowered efficiency)
-Also for research: Increase the time it takes for each research to be done so it makes a more challenging effort to get solar panels level 100 and have over 9000x the efficiency.
-Have a more expanded world and maybe add vehicles you can travel in to get to mines farther out (since you would have mined the closer ones (earlier suggestions) and maybe you can order your colonists to do some of the work for you (DM for what I mean)
-Add a way to go inside colonist house and maybe some customization to that.
-Add a cave system with various streams and maybe even huge lake underwater sections
-Add a mountainous desert terrain (It is an extra-terrestrial planet so as far as we know so go crazy dude!)
-Add some animals or such to the game making it have a less lonely feeling.
-Maybe some cacti or dead plants and fossils (Even just for aesthetic purposes!)
-Add a story! Could even be a copy of a similar game such as Subnautica's but it would be great to know what we are getting in to. Or it can be what it similar to the ships screen that you are a settler, but create a nice little story line at the beginning.
-Add a Co-Op system
-Add upgradable buildings, or just make it once you research you can get the building, and maybe enable it that you need resources (not only credits) to build certain things. This refers to more than just housing, even if the upgrades are mostly aesthetic.
-Add a later end game state, maybe make it so the landing platform can transport people to your colony, or even to different planets to colonize there. It just seems like so much untouched playability.
-Dude, add a damn price tag, this is not some low life game, I get it does not need one right now but definitely get it up later!
I will keep adding suggestions later on but I invite you to add me on discord: Jevil_FromVSauce#2753 if you want to talk more! I am glad to help out in any way I can, if I have the ability to do so! But most importantly, keep up the good work, this is going somewhere!