So, first of all, the cursor is a sauropod. Possibly a brachiosaurus? This fact alone is worth a star.
Quintessence brings a nice combination of physics and whimsy. It asks the player to think a bit about the nature of such lofty subjects as cosmology, consciousness, and agency; but it does so in the context of a lighthearted, cat-centric reality. Definitely an imaginative piece.
Apart from aforementioned sauropod, the graphic elements include pleasant images of the cosmos. What's less pleasant, however, is the fact that the text tends to fade into the busy backgrounds. Even with black outlining, I found that the text was often a strain to read.
The most intriguing thing here, in my view, is the idea of embodying the universe, its rules, and its destiny in conscious entities: the cat and the particle (and its permutations). This allows Quintessence to inject an element of pathos into what would otherwise be cold, impersonal aspects of reality. Neat. But I feel that it didn't run as far with this idea as it could have, and a deeper dive into the psychological and (for lack of a better word) interpersonal aspects of the characters' existence would have made this game into a more compelling mythology.