What are some good games for a nervous horse?

I recently started training a 6-8 year old mare, who is very sweet but has some issues. She is very easily spooked by the wind or new objects, and I've been working to desensitize her. We are just doing groundwork for the next few weeks, and I'd like to get some opinions on what games can help her loosen up and bond with me. Like I said, she is very sweet and already broke but spooks over many normal things as if she's never seen them before.