Chōsenshi Densetsu: Assault from the Sea serves as a prequel to the webcomic Chousenshi Densetsu, about a band of legally-sanctioned vigilantes fighting against criminals and supernatural forces, that consisted of a single story in 2006.
Notably, Assault from the Sea is the second attempt at a game based on the comic; Chōsenshi Densetsu: Dynastie Rising was an action game - also designed as a prequel - which had a demo release and a significant amount of advertisement before falling into Development Hell.
C-Dogg is tinkering in his garage, when Ace alerts him of strange creatures rising out of the Pacific Ocean. The S and Trina run into them as they are on their way out to investigate; the four of them hop aboard C-Dogg's hoverboards and set out to stop the monsters.
Assault from the Sea is a simplistic vertical-scrolling shooter. Players are given a melee attack, two projectile attacks (one standard, and one that hits a larger area but is less powerful), and a special attack.
Power-ups include Autofire, Spread Shot, Unlimited Special, and the ability to use Brandy the dog as an Option.
A version of the game is being developed for Japanese release with a changed story, sprites, and aesthetics, centering around a band of pirates, called Kaizoku Wonderland (海賊 WONDERLAND).