When I adopted Brasco, he was afraid of toys and would pee when he heard them squeak.
And he would not even go near one. But I did have Luigi, and he loves his toys and loves to chase after them. Brasco finally got used to the noises they made and would just sit right next to me and watch Luigi play. He did that for about 2 weeks. Then one evening out of the blue, I threw this toy for Luigi to go get, and Brasco jumped from the couch and ran and got it! He grabbed it, then dropped it, and ran right back to the couch. He did that a few more times over the next few weeks. Then eventually,he got that he could bring the toy back and let me throw it again! Luigi was even like....WHAT???? LOL!
So it takes time. If this little one was alll cooped up in a cage, he has no clue about life itself. And how could he could have. Just keep giving him lots of love. Maybe start off with a string or something to see if there is any interest! Brasco used to also love to just play and "bite" at my hand! Over time, he will come out of his shell. I look back at this time last year with Brasco, and he was sooo shy, and timid and very nervous all the time, and now...WOW...what a world of difference! He is fun, feisty, full of energy, and loves all his toys! He will even play with them by himself, and flip them in the air and chase after them! Its sooo cute!
Good Luck!