For a fun indoor (or outdoor) gross motor activity, we had a jumping contest. I put down a line of masking tape, had Love Bug stand behind it, and then had him see how far he could jump. And then he did it again to see if he could go farther. It could also be a group activity where it’s really a contest to see who could jump the furthest.
He also enjoyed jumping once and then continuing to jump across the room. That seemed to be more fun for him!