Information in the game database is updated periodically. Below, you'll find that information compiled as pertains to Gainax. The company may be involved as a publisher, developer or both.
Neon Genesis Evangelion: Ayanami Ikusei Keikaku [April 18, 2002]
Princess Maker 2 [September 30, 2004]
Neon Genesis Evangelion [March 1, 1996]
Neon Genesis Evangelion 2nd Impression [March 7, 1997]
Neon Genesis Evangelion Digital Card Library [September 25, 1997]
Princess Maker 2 
Yoshiyuki Sadamoto Illustrations [November 27, 1997]
Princess Maker: Legend of Another World [December 15, 1995]
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.