Short answers, pulled from the story.
Project X Zone is a tactical role-playing game developed by Monolith Soft and published by Namco Bandai Games for the Nintendo 3DS. It features sixty playable characters drawn from Namco Bandai Games, Capcom, and Sega, spanning franchises such as Tekken, Street Fighter, Resident Evil, Virtua Fighter, Mega Man X, Sakura Wars, and Valkyria Chronicles III.
Project X Zone released in Japan on the 11th of October 2012. North America received it on the 25th of June 2013, and Europe on the 5th of July 2013.
Project X Zone sold over 400,000 copies worldwide, according to Bandai Namco. Western sales exceeded ten times what Bandai Namco had anticipated, and the game placed among the best-selling 3DS titles in the United States and the top twenty best-selling games in the United Kingdom.
Both theme songs were performed by Yoko Takahashi. The opening song is titled "Wing Wanderer" and the ending is titled "GALAXY." The opening movie was produced by animation studio Trigger, founded by Hiroyuki Imaishi and other former Gainax employees, and directed by animator Akira Amemiya.
Project X Zone holds a score of 70 out of 100 on Metacritic. IGN's Scott Thompson gave it an 8 out of 10, while GamesRadar awarded a 2 out of 5. Kotaku's Mike Fahey included it in his top ten games of 2013.
Project X Zone 2 was released for the 3DS in Japan in November 2015 and in North America and Europe in February 2016. It follows the same crossover format as the original game.