Shelter is a fun, simple and beautiful game and while certainly worth your time, it's not worth $10, wait for a sale!
The good:
-Comfy and relaxing
-Eye Candy The cartoon graphics and art direction are unique, artistic, and beautiful.
(However, some people might not like the fact that the colors are a bit whitened/cloudy, probably by a filter, and would like a more saturated color. The game is still really colorful anyways and no one will have any complaints on the graphics, it's just a minor preference.)
-Audio is just as good with fitting relaxing guitar clips and wild jungle drums and nice sounds of nature and your cubs' adorable calls.
-Emotional: You will genuinely care for your cubs, feel sadness, and wonder too. There'll be a few tense and exciting moments too.
The bad:
I love the game, but since it is so short and lacks any extra features I wouldn't recommend it for $10, wait for a sale so it is $2-4, and still that is a bit pricey considering you can get huge games for those prices during Steam sales.