I've just finished your game in digital format and I must say that I'm impressed! Decided to buy full version just after finishing demo and definitely was not disappointed!
Game world is perfectly executed - it is atmospheric and mysterious, yet hostile and dangerous. It really gives you the vibe of being on some unfamiliar celestial body with no friendly face in sight. Story is very well written and given in right amounts - not too much, not too little, just enough to motivate player to explore further. First game that you will compare 2021 Moon Escape to is obviously Link's Awakening, but it absolutely isn't a clone in any sense. It's the sense of mystery and fun of exploration that those two games share, but 2021 Moon Escape has its own Identity and brings a lot of fresh ideas - interesting puzzle sections and immersive menu screen among others.
One thing I didn't like is that if you open menu and close it, all enemies on given screen respawn. I understand that its like that by design, but I was irritated a few times when I defeated all enemies in the room and opened menu to check something quickly only to realize that I have to fight them again. But I would say it's tiny inconvenience.
To sum up, this is very solid experience that left me thirsty for more! I hope you plan to do some follow-up in closer or further future 😄.
P.S. I got 100% of items and was given a choice to fight final boss or back off. I checked both paths and it seems that it doesn't affect scene after credits. Is that supposed to be that way?