Play time for indoor cats is supposed to mimic the need for hunting.
My cats love toys that are made with real rabbit fur and feathers.
I've gotten some pretty realistic mice made with rabbit fur at A Pet Lovers Warehouse. They even squeak when squeezed, haha it was hilarious when my cat started chewing on it and it squeaked. He jumped back and stared at it for a couple minutes.
I regularly spray these toys with liquid catnip to encourage them.
I've also bought them a larger stuffed animal, so they can "kick" it like they would do to real prey.
Paper balls, crumpled up from flyers are great to. You can also use tinfoil, but requires supervision so they don't eat it.
And hair ties, they love hair ties. Or hair clips. And the laser pointer.
This a great website for indoor pet health.
https://indoorpet.osu.edu