Design faults were heavily reported shortly after release, both minor and major. One such fault reported by IGN was that crouching players did not experience speed restrictions.
Player-versus-Player combat was of particular focus to reviews. Fighting was compared with the "damage-absorbent" matches in Halo, with IGN adding that actually killing a player felt to much like a chore. Further, the "clunky" controls and slow reload speeds were said to take too long, making individual fights much longer. The "Brainer" weapon was also subject to criticism due to such an overpowered weapon being available to all players immediately, effectively making level progression for better firearms completely unnecessary. While praise was given to the designs of the maps, they were seen as too small, leading to players often spawning close to enemies or in front of Zombies. The Zombies themselves were seen by reviewers as more of an environmental hazard to players than serious enemies, favouring instead the PvP approach in most shooters. IGN praised DNA Hunter as the best gametype, but noted it was the only game to seriously use the Zombies.
The game's equivalent to a story mode, "The Experiment", was seen by IGN as a failed attempt to add tension. While they liked the prospect of having to restart the game after a single death, the large availability of health items was seen as where the game "defeats itself".