At least six shorts were produced, although only two of them have surfaced--Cucumber and Potato, the latter of which is incomplete. In addition to the full version, at least 4 other shorts remain at large: Baby Corn, Zucchini, Celery, and Broccoli. Although the six known shorts have been uploaded to Nick.com, a glitch in the video player prevents the shorts from playing. 
Update 1/17/14: The full version of Potato has been uploaded by Mr.Unique!
Update 5/23/15: Icons of the shorts (along with icons of Balinese Slapping Fish) have been found on Nick's website; however, the videos do not work. Zucchini's icon still has to be seen.
Update 11/26/15: Broccoli And Babycorn have been uploaded by Caramell95! (A.K.A CatscratchFan4004 on YouTube) https://www.youtube.com/watch?v=3t64rDuFq4E - Broccoli https://www.youtube.com/watch?v=rJxJNaNybh4 - Babycorn
Update 12/25/15: Celery has been uploaded by Caramell95! (A.K.A CatscratchFan4004 on Youtube) https://www.youtube.com/watch?v=iCYOgm1kgsw
Update 12/28/15: A screenshot of Zucchini has been found!