I purchased the UFO gun from toy story 3 pc game but when I click it, it won't let me have it, I have used it once, can someone explain?

• The UFO gun

As Toy Story 3: The Video Game progresses you are able to collect prizes, one of which is the UFO gun.

For a gamer to acquire this you must first collect the different parts that make the weapon. Once this has been completed end the level by blowing up the dam, and on completion the gun will be dropped to you as a present by a stagecoach.

Alternatively you may attain the gun in story mode by purchasing it for $2000 at Al's Toy Barn.

Toy Story 3: The Video Game, is based on the popular award winning film made by Disney Pixar.

• Details

Published by Disney interactive studios, and developed across various platforms (XBOX, Playstation, PC, Nintendo DS) by Avalanche software, Asobo Studio and N-Space. The game was first released in June 2010 to coincide with the release of the much anticipated final film to the Toy Story trilogy.

The game is based on the storyline of the film itself and includes the popular characters of Woody the cowboy and spaceman Buzz Lightyear.

The narrative of the story follows Woody as he attempts to free the other toys from the Sunnyside day nursery and includes cameos from other characters including Bullseye the horse, Hamm the pig and Jessie the cowgirl.