Art : Super nice
Music : Amazing!
Story : Interesting, a bit hard to hop in but really mesmerizing once attached
Ambience : Great sucess, thanks to the above
Gameplay : ...uhh... eh...?
I won't review the art, music and ambience, they are mastered beyond my knowledge in these domains. I don't see anything worth change. I can't even find the words to describe what make them as good as I found them :)
The story was a bit hard to get into because the characters weren't introduced (for ex. the main character - who is he? where does he come from? what's the current context?). Also, the justification for the title of the game comes too quickly; usually that's something that feels better toward the end of the game. If given too early, it feels a bit like getting rid of a story element.
Also, a tiny plothole (potential spoilers?) : why wouldn't the rescue crew accept the main character and their crystal before it turns black? They can let the crystal finish "aging" inside the rescue ship rather than in a deteriorating ship, it's much safer and it saves a lot of time (one or two days?).
Frankly, neither are a big deal. The story is still really cool and worth [reading? scrolling? clicking through?]
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Now, for the real problem...
The gameplay... I understand it's a visual novel, but most visual novels involve more player activity than clicking for progress.
Usually, there are frequent decision making, in the forms, as you said to another reviewer, of dialogue choices or minigames. That helps the player to identify as the main character, which is, to me, an ultra-important element of visual novels. I need to believe that the character's choice are actually my choices, and giving me a list of options to progress can help creating such an illusion. The single choice I had in this game felt quite... fake. I can take any of those in any order, it'll do no difference and I'll end up picking them all anyways.
The minigame at the very end was quite interesting. Not too long, not too hard; still, I'd have two complaints :
1) It felt like a rushed way to split the ending. It's a bit cliché to do an obvious good ending vs. bad ending, especially when the difference between both require absolutely nothing from prior to the minigame. It feels like everything I did in the game before the minigame had no impact whatsoever on what the ending would be, and the result of the minigame was too obvious to feel like a real choice.
2) No retry button. I failed the minigame three times before succeeding, and each time I had to start the entire game over and over again. (Also, I had to refresh to start again; letting the game start over bugged the mouse, which I couldn't move after the game was completed once.)
The gameplay (or lack thereof) is the biggest problem here. Don't waste the entire idea, it's a really nice one, I'd just recommend something that's more interpelling and requires more than simply clicking.
I feel like the NG emote from the score I give is representative of how I feel about this game; I feel it's a quite interesting game, not exactly something that's complete as it is now, but definetly something worth building upon.
Good luck with your future projects!