A tier list is a list of playable characters of a video game ranked by their respective viability in competitive settings.
 Characters listed high on a tier list of a specific game are considered to be powerful characters compared to lower-scoring characters, and are therefore more likely to be used during tournaments.
 Tier lists are popular in fighting games such as the "Street Fighter" and "Super Smash Bros." series, and MOBA titles such as "League of Legends" and "Dota 2", in addition to hero shooter titles such as "Overwatch" and "Paladins".
Tracer (also known by her real name, Lena Oxton) is a player character appearing in the 2016 video game "Overwatch", a Blizzard Entertainment–developed first-person shooter, and its related animated and literary media.
 Tracer is from the "Overwatch" universe, but she was introduced as a playable character in Blizzard's crossover multiplayer online battle arena game, "Heroes of the Storm", in an April 2016 update.
Olivia ""Sombra"" Colomar is a character in the fictional universe of "Overwatch", a 2016 video game developed by Blizzard Entertainment, and the subject of a related alternate reality game (ARG).
 Throughout the game's open beta, clues regarding Sombra were placed into a map called Dorado, a fictional town in Mexico.
 Hints about Ana Amari were placed into another map at the same time, and confusion over the two led initial speculation believed the two were a single character.
 The alternate reality game continued through November 2016, spanning official Blizzard videos, the Battle.net forum, websites representing fictional entities in the "Overwatch" universe, the game itself, and the "Overwatch" subreddit.
Lego Batman 2: DC Super Heroes is a Lego-themed action-adventure video game developed by Traveller's Tales, for the PlayStation 3, PlayStation Vita, Nintendo 3DS, Wii U, Wii, Nintendo DS, Xbox 360, Microsoft Windows, Mac OS X, and iOS.
 The game is a standalone sequel to "" and the second "Lego Batman" video game.
 Numerous DC characters within the Batman continuity and outside it are playable characters.
 "Lego Batman 2: DC Super Heroes" also featured dialogue and an open world to explore, the first in the Traveller's Tales's Lego series to do so.
 The game was released in North America on 19 June 2012.
 The Mac OS X version of the game, published by Feral Interactive, was released on 6 September 2012.
 The Wii U version was released on 21 May 2013.
Overwatch is an American digital comic series published online by Blizzard Entertainment and republished by Dark Horse Comics' digital service, featuring events surrounding the characters of the "Overwatch" universe.
 The title was launched on April 21, 2016, and has continued to be published with no set schedule.
Psychic Force (サイキックフォース , Saikikku Fōsu ) is a 1995 fighting arcade game created by Taito which was later ported to the PlayStation in 1996 and 1997.
 The PlayStation version was released by Acclaim in North America, and in PAL regions.
 The game was a 3D fighter which had combined the normal features of an arcade fighting game with psychic powers.
 There were eight playable characters available to choose from in the game and a final boss/secret character who is playable through the use of a code.
 "Psychic Force" was released without much hype and was not commercially successful at the time of its initial release, but the series has since gained a strong cult fanbase.
 "Psychic Force" would later get an arcade-exclusive update titled "Psychic Force EX", which was released a year later in 1996.
 "EX" would make Keith, the final boss/secret character of the original game a playable character without having to initiate a code and that the characters would receive new color schemes for their costumes while the gameplay was improved and balanced.
 In 1998, a sequel was released under the title "Psychic Force 2012" also for the arcade, and was later ported to the Dreamcast console in 1999.
 It was eventually adapted to the PlayStation under the title "Psychic Force 2", which was released in Japan on October 7, 1999 and later to the PAL regions in 2001.
Smite is a third-person multiplayer online battle arena (MOBA) video game developed and published by Hi-Rez Studios for Microsoft Windows, macOS, PlayStation 4 and Xbox One.
 In "Smite", players control a god, goddess, or other mythological figure and take part in team based combat, using abilities and tactics against other player-controlled gods and non-player-controlled minions.
 The game has multiple player versus player modes, many playable characters, and has a successful esports scene with multiple tournaments, including the annual Smite World Championship which has a US$1 million dollar prize pool.
Tekken (also known as Tekken 1) is a fighting video game developed and published by Namco.
 It was released in arcades in December 1994 and on the PlayStation in 1995.
 It was the first entry in the popular "Tekken" series, succeeded by "Tekken 2" in August 1995.
 The arcade game features eight playable characters, while the PlayStation version features 17 playable characters in the roster.
Wayward Souls is an action-adventure video game developed by Rocketcat Games and released on April 24, 2014 for iOS.
 A PC version is currently in development.
 The gameplay resembles that of "" crossed with the randomly generated dungeons of a roguelike and the escalating challenge of the "Dark Souls" series.
 Rocketcat has continued to update the game since its launch, adding new playable characters and increasing the base price of the game.
 Currently, the game has six playable characters.
The team-based first person shooter video game "Overwatch", developed by Blizzard Entertainment and released in May 2016, features 25 playable characters (heroes) and a number of supporting characters as part of the game's narrative, which is told through animated media and digital comics outside of the game.

Question: Overwatch is a comic series featuring character of a universe, from which there are how many playable characters in the video game version?
Answer: 25