I can easily say that Echo is one of the best, if not the best furry visual novel
It's not a typical dating simulator or "choose this route and you'll become lovers with this character, happy ending"
It destroys that typicality and tells traumatic stories with thrilling writing that leaves you with different emotions for a while when you finish the reading
Every main character (even some of the minor characters) has their own unique story which will leave some impact on you
The visuals (sprites, backgrounds, CGs, music etc) are also done great, they perfectly fit the story atmosphere and convey the characters' feelings/emotions to readers
If you're looking for interesting visual novels to read, I'd definitely recommend Echo (and also the other novels from The Echo Project since they are equally as great as this one)