I only played this game way after it came out. I remembered hearing that it was good, but didn't think much of it since I didn't really hear much else about it. After having played it, holy smokes I understand why. Learning more about the game beyond just the store page description would be detrimental to the experience given how this game is structured, but I'm here to tell you that the game is SO much more than what it looks like. Don't sleep on it.

As others have said, but bears repeating, this game can only be truly experienced ONE TIME. This is because progression in the game is solely based on gaining new pieces of information from exploring the solar system. Once you have all the information you need, you can beeline it straight to the end of the game. So not much replay value, but I would divorce my wife to play this game for the first time again, so it's worth it.

This game provides a unique and magical experience. It's unlike any game I've ever played.

Read no more about it. Get both the main game and DLC. It's phenomenal and will change you.

100% Achievement Completion Perspective:
This game challenged me to 100% it. Nothing is missable and most achievements are doable, but two of them are some of the hardest achievements I've ever had to get. One felt like it required a rocket science degree and the other tested my patience to an insane degree. I felt like I absolutely earned those achievements. There are many DLC-specific achievements, but, let's face it, there's no way you're going buy the base game without getting the DLC too. It's just too good.