The story, which is based on Norse mythology, follows the divine warriors Freyr and Freyja in their war against the Jötunn, which heralds the coming of Ragnarok.

[1] Players take on the role of sibling deities Freyr and Freyja, completing missions that involve defeating waves of enemy troops.

The latter also incorporates use of the Wii MotionPlus expansion, allowing players to use weapons by mimicking actions, such as slashing with a sword or drawing a bow.

[1][7] Weapons range from standard swords and axe to bows and magic staves, which fire explosive projectiles that can damage both enemies and allied units.

There are checks to ensure participants have equivalent weapons and armour to the host to prevent mismatching, and story missions are marked for players who have not reached them in their version of the game.

During gameplay, players coordinate and communicate through shouts triggered using the Wii Remote's D-pad, and in-game alerts if a character is low on health.

The situation is worsened by the emerging armies of Niflheim and Muspelheim and three demonic weapons whom Loki created during an earlier war with the giants.

When production of Chōsōjū Mecha MG finished in 2006, the team were given the go-ahead to work on Zangeki no Reginleiv, though both sides were wary of its scale.

[9] The early concept focused simply on making a fun game where players could slash at enemies, with the setting being a secondary consideration.

[9] The game was first announced at a special Nintendo press event in 2008 under the provisional title Dynamic Zan, with a planned release for the following year.

[14] To promote the game, Nintendo partnered with media retailer Tsutaya to loan trial versions to customers from January 21 until release.

[18] By this point, Nintendo had several third-party developers and publishers creating mature games for the Wii, but Zangeki no Reginleiv was their first self-published work.

[5] Keza MacDonald of Eurogamer was fairly mixed, enjoying the gameplay style despite control issues, but finding the story flimsy and criticizing the graphics and cutscenes.

[7] Siliconera's Spencer Yip found the controls difficult to handle, but praised the coop multiplayer and enjoyed the gameplay style.

[2] In a list of anticipated Wii titles, Cubed 3 lauded the game's potential and felt that players would enjoy it due to its style and combat system.