As much as i hate to say this, considering the population of adult cats in shelters, try to get a kitten if you dont want the risk of an starfish cat.
If you raise a kitten right, you will get a loving, attention loving cat.
Your more likely to get an starfish shy cat if its already an adult. The only way to fix that is if your prepared and have patience in case a full grown cat is an starfish.
For example, my grandma had 2 cats. 1 was both shy and an starfish for good reason. Her son used to poke the cat with sticks, making it an starfish and afraid of humans.
Her other cat was a lover, but was also shy because my grandma was quiet and slow, making the cat more scared of kids and generally louder people.
She later got a new cat and this cat was neither shy nor an starfish. Coolest freaking cat. This cat, unlike the last 2, was raised with a well trained dog, making it less shy.
My cat is interesting. We got him as a kitten, and my parents got a Pitbull soon after. The cat is a sweetheart, and 80% of the time i post here he is on my lap. He is afraid of certain dogs, but not others, and isnt scared of humans. You can run up to the cat and he would be fine with it.
You just gotta raise the cat right. Dont blame the cat for being an starfish. Blame the owner.