Information in the game database is updated periodically. Below, you'll find that information compiled as pertains to Handheld Games. The company may be involved as a publisher, developer or both.
Disney's That's So Raven: Psychic on the Scene [November 2, 2006]
Dr. Seuss: Green Eggs and Ham [November 17, 2003]
Dragon Tales: Dragon Adventures 
Little League Baseball 2002 [May 27, 2002]
MLB Slugfest 2004 [March 18, 2003]
Nancy Drew: Message in a Haunted Mansion [November 15, 2001]
Phil of the Future [September 18, 2006]
Super Duper Sumos [October 26, 2003]
Dragon Tales Adventure [November 15, 2001]
MTV Sports: T.J. Lavin's Ultimate BMX [December, 2000]
Portal Runner [September, 2001]
San Francisco Rush 2049 [September 7, 2000]
Tech Deck Skateboarding [March 25, 2001]
There are numerous companies in the industry, and their names change like the weather. The information above is not particular about the finer details. Acquisitions are common, so companies with no recent listings may still be developing games under a new name. For example, DMA Design currently has a Rockstar name. Do you know of a title that is not listed above but should be? Be sure and let a staff member know. You can contact staff if you click here.