4M Robot Kit: Smart Robot, Robotics Science Kit, Ages 8+, Includes All Parts & Instructions, Requires 1 AA Battery

This is probably the best robot you can buy in the $10 range. It's not a robot in the true sense, because it has no problem-solving skills, but it has an ingenious way of mimicking artificial intelligence -- whenever it runs into something, it turns around and goes a different direction. I still haven't figured out how this little guy works internally, but there's a motor spinning around inside the ball that's hidden underneath the casing that you see in the picture. It's very entertaining watching him scoot around on the kitchen floor, bumping into cabinets and trying out a new path. My family even agrees that this toy is more entertaining than some of the more expensive and real robots that I've purchased. Definitely worth the money!

I build these in our robotics summer camps and they work great as long as you install the motor completely to the bottom so that it does not interfere with the top once it is installed. Otherwise it will not rotate properly. Make sure you push the motor all the way in.We set up a obstacle course for our kids to have a robot war/course to run through. First robot to the other side wins!

I saved this for my grandson to put together over Christmas break. He followed all directions as I supervised and when he was ready to test it, it didn't work at all. What a disappointment. He even said that I should have just took the money I paid for it and burned it.This was a real waste of money.

A nice simple project for kids maybe 6-10, but most fun for cats to watch bumping around the kitchen. The plastic parts mean it's not super-durable but it shouldn't be undergoing any rigorous play in any case.

Simple design. Easy to assemble - it took me and my daughter about 5 minutes.DC motor casing, battery holder cap and weight fixture are of poor quality. I definitely would not pay more than 10 bucks for this device.It is fun to watch it crawls from obstacle to obstacle though.