The gameplay combines tactical RPG and action sequences during battles, featuring characters from video game series owned by Namco and Capcom.

The project was proposed by Monolith Soft to celebrate Namco's 50th anniversary, and Capcom was contacted as a partner due to their large character roster.

First announced in January 2005, the game was never released outside Japan, a fact attributed to the obscurity of some characters and the scale of its script.

Following Namco × Capcom, Monolith Soft would work on some other crossover titles, including the successor Project X Zone in 2012 for the Nintendo 3DS.

They can also purchase items for healing or character boosts at shops using currency won during battles and through a gambling minigame activated between certain story chapters.

The game's turn-based battles play out in a grid-based arena from an overhead perspective; each unit on both sides has their turn placed according to their current AP.

[5] The player party can also engage in a defensive battle when attacked, with successful defending decreasing or nullifying damage and regaining AP.

Reiji's father Shougo fought Saya to prevent this ten years before and was forced to sacrifice himself with Xiaomu's aid to succeed.

The game was directed and written by Soichiro Morizumi, a former employee of Banpresto and veteran of their Super Robot Wars franchise.

[7][8] Development began in 2003, and was initially proposed by Monolith Soft as an internal crossover of Namco characters for the company's 50th anniversary.

[5] The game was never released internationally, with several outlets citing both its large amount of text and a lack of worldwide recognition for many of the represented characters as potential reasons for this.

[1][2][3] A fan translation was created by a group called TransGen, made up of ten development team members and thirty beta testers.

[26] Japanese magazine Famitsu positively noted the use of kyōgen comedy routines in dialogue, but found other characters lacking development.

[27] Siliconera similarly noted shallow and repetitive gameplay, but said that fans of both Namco and Capcom would enjoy the crossover elements.

[3] Anoop Gantayat, writing for IGN, found the visuals lacking despite the game's hardware, and called the story structure "pretty plain".

[2] Following the release of Namco × Capcom, the two companies would collaborate on future projects, particularly Street Fighter X Tekken and the Mobile Suit Gundam VS series.

[28] The Namco × Capcom development team would later collaborate with Banpresto on the 2008 Nintendo DS game Super Robot Taisen OG Saga: Endless Frontier.

[32][33][34] Its 2015 sequel, Project X Zone 2, would be developed solely by Monolith Soft and feature additional collaborations with Nintendo franchises.