This toy has some trigger problems: the trigger design is so complicated that it is hard to fire it even for an adult. The overall toy is great, and is nice that the bow is actually powering the dart (unlike some other Nerf toys that have the bow just for design).
To solve the trigger problems just unscrew the 5-6 screws that hold the toy together and put some grease (Vaseline) on the metallic bolt of the cam that pushes the string out. This will make the trigger work very smooth.
While the toy is open you will see that there is a second mechanism that prevents the toy to be fired, unless a dart is loaded. This is written nowhere on the box. If you want to cancel that mechanism, you can pull it out. Also you can leave it in and, after you assemble back the toy, use a rubber string to push that mechanism back so that it will not prevent the trigger from firing.
Overall, a great toy, too bad it comes crippled by this trigger problem.