Yacht Club Games envisioned Showdown as a small minigame similar to modes in Mega Man 7 (1995) and Super Mario Bros. 3 (1988).

[1][2] Players battle using one fighter from a roster of twenty different characters in the Shovel Knight franchise, all of which possess their own movesets and fighting styles.

[5] One mode called "Treasure Clash" centers around collecting gems that appear around the level as quickly as possible, while claiming the jewels of other players by slaying them.

[2] A special mode called "Chester's Choice" allows the player to randomly set these modifiers, leading to distinct battles with different combinations of stages, items, teams, and other features.

[1][3] A special minigame must be completed to progress through the campaign; it requires the player to break several moving targets to achieve a set score.

The developers originally intended for Showdown to be a minigame similar to game modes in Mega Man 7 (1995) and Super Mario Bros. 3 (1988),[8][9] though the team gradually made it more ambitious.

They described the finished product as similar to a party game, yet more expansive and complicated, comparing it to a Super Smash Bros.

Yacht Club Games originally called the mode Roulette, but eventually renamed it after Chester, a character from the franchise who acts as a merchant.

[11] The game was launched concurrently with the downloadable content (DLC) campaign Shovel Knight: King of Cards on December 10 for Windows, macOS, Linux, PlayStation 4, Wii U, Xbox One, and Nintendo Switch.

[2] GameRevolution said that the modes helped make the game feel chaotic and fun,[7] while Vandal found the combat too intense and disorderly to be entertaining.

[1][2][4] Nintendo Life considered their movesets unique, saying that the inclusion of boss characters from previous games was good fan service.

[7] Game Informer found the story mode repetitive, saying that it would dissuade players from completing it to unlock new characters and stages.

[1] A few critics highlighted the boss battle,[1][7] with GameRevolution writing that it was reminiscent of earlier Shovel Knight games and "delivers on everything you'd want from the series".