the main flaw is that it only runs 15 minutes out of every hour. They need a better cycle, such as 10 on, 20 off. Other than that, the battery does last a long time. Of course it does, because it hardly ever runs. There's a very good supply of velcro straps for it.The string they have with it sucks so buy better string. It's hard for me to find the right one. The really strong slick ones are hard to tie into a knot and I don't have the science down yet, but unfortunately you have to tie the string around the loop on the toy so you have to be careful when it comes time to cut the string off. Now I have to buy more toys because I'm not too great with my fingers or my eyes.