The main point of this toy is to use your fingers to kick a miniture soccer ball or football into a goal. This toy is basically a two-in-one type of system. It starts off as a rectangular box (2 x 6 x 8 in), and the child can choose to play either soccer or football. To play soccer, all the child needs to do is lift up the soccer net from the inside and take out the soccer ball from an inner compartment. To play football, all the child needs to do is take out the field goal post from the middle of the box and stick it into the whole in the back of the box, and then once again take out the football from an inner compartment. From there, the player simply uses his fingers to shoot the ball into its proper goal. This box is adjustable so that the player can take shots from a longer distance.
The physical principle this toy is based on is projectile motion - by using a force to move the ball to some target.
The cost to construct this toy would be very very cheap, considering it is a small toy and mostly made of plastic. The toy is not incredibly durable, since the soccer net and field goal post seem like they could break off easily. The only significant safety issue with this toy is the small balls because hey are small enough to swallow, but they are attached to a string that will prevent kids from separating the ball from the toy.