The core concept did not change over the course of development, though the other content did. It was his first attempt at networked multiplayer. He read about 'programming and fighting game structure' over the course of development, which he credited as important towards the game's progress. Messhof also asked a former student to help him complete the game's netcode, which he deemed to be 'totally essential' for the game's future as an eSport. He felt lucky to have Daedelus as his composer. Messhof described their process as wanting to 'enhance the action' while letting players control the game's tension. Daedelus designed some of the procedural elements that trigger the music sequences. Their list of desired styles always included Daedelus, who they were able to contact through a mutual friend who attended high school with the musician. She led the search for the game's musician. The game languished until Kristina 'Kristy' Norindr assisted Essen in founding Messhof LLC, a legally incorporated indie studio, joining as a co-founder and working in a business development role. Messhof worked as the game's only programmer and his time was divided between development and his other freelance and personal projects, graduate school, and a job teaching at University of Southern California. The game was delayed as Messhof planned a formal release and later renamed Nidhogg, after the mythological Norse serpent who appears in-game. It was commissioned for the New York University Game Center's first No Quarter annual multiplayer show and first exhibited in April 2010 as Raging Hadron. Inspired by the 1984 fighting game Great Swordsman, the game was made by indie developer Mark Essen over the course of four years, using GameMaker Studio. It can be played via a shared keyboard, and its art style has a pixelated aesthetic similar to games of the 1980s, with vivid colors and simple graphics. The game also has a tournament mode and game variants including ' boomerang swords'. Nidhogg has four different levels and single-player, local multiplayer, and online multiplayer two-player modes.

The player to reach the end of their opponent's side first wins and is eaten by the mythological Norse serpent NГГ°hГ¶ggr. The player continually pushes towards one side of the screen, such that they are permitted a few seconds to run towards their opponent's side while their opponent respawns after dying.

Players can also dive kick, wall jump, climb ledges, and crawl. The player-character's sword can be held at three different heights: low, medium, and high, and changing the sword's position to hit the opponent's sword will disarm the opponent. Players can run, jump, slide, throw their swords, and fistfight. Nidhogg is a fast-paced two-player dueling game where two players sword fight in a side-scrolling environment.

Nidhogg online multiplayer