I just got the link to the early access version and tried it. I just finished the first two tutorials, so this is not really an complete review but only the first impression.
The main menu looks quite cool, I like it because it looks to clean but also has this nice planet in the background, it makes a really good first impression and makes me wanting to play the game. The ingame graphics is also quite clean, but I guess a couple of textures are still missing so I can't finally judge it. I really like the surface with the different materials, looks cool. However, I noticed that the HQ has only a single landing spot. After a while, so many landers are landing at the same time, that it looks a bit stupid. Maybe a bigger HQ model could support multiple landing sites, so that it looks better and not as crowded/overlapping.
The gameplay is easy to understand, I figured most of it out in no time. For now, I think it might be too easy, but since I haven't seen much of the whole game I guess that is just because I've only player the first two tutorials. But anyway, I'm not a worst-case user, you might want to add a more detailed tutorial on how to build structures and how income, buy/sell etc. works.
During playing the tutorials, I missed a window where I could look up the mission target. I canceled my first attempt of the first tutorial because I was thinking of doing something wrong, because I expected a message after I upgraded the HQ for the first time. I had to cancel the game in order to view the mission goals again.
During the first tutorial, I was irritated because the stock market buttons in the upper right where not working. I would suggest to hide them or place a note, that they are disabled for that tutorial.
The only thing I didn't figure out was, how that black market stuff works. On the lower right I see the window and it says black market is available, but even if I have enough money, I can't use the buttons. I guess they are also disabled in the second mission? Then a small note should say so.
Overall, my first impression is a very good one. I experienced no crashes, the game looks and feel nice and the stuff that I noticed above are just minor (and I guess fast to fix) issues. Thanks for this cool game!