Balloons are one of my favorites for cheap, easy entertainment. Many days you'll find me carrying one in my pocket for a one-on-one visit; a quick game of batting one across a table top or up in the air can make even the grumpiest senior smile. There's something about a balloon coming towards you that people can't resist- they automatically reach out to hit, catch, touch, or otherwise interact with it. I often used balloons to keep residents occupied before meals when I worked in skilled nursing. We'd gather around a table and try to keep the balloons moving but off the floor. We hit them with our hands and sometimes bounced them off our heads. Depending on the abilities of the individuals present, sometimes we hit them with fly swatters, paper fans, or paper plates... but mostly we just used our hands. Besides just playing around with them, balloons are great for art. You can draw on them, put some paint on them and use them like stamps for interesting texture
