Obsidian became the game's lead developer, while Neverwinter Nights creator BioWare provided technical assistance.[17] While they were developing the game, the team's size grew to about 50 people.[5] The team were given sufficient time for the game's development, and Atari was willing to delay the project's targeted release window from Christmas 2005 to October 31, 2006.[15] Neverwinter Nights 2 received a generally positive critical reception.[18] Two expansions, Mask of the Betrayer and Storm of Zehir, were released in 2007 and 2008.[19][20]