Tech Romancer is a 1 on 1 fighting game in the same vein as King of the Monsters: the player controls a massive fighter that squares off against another fighter with the environment that the two battle in taking damage as the combatants are hurled around. The game features a simple combat system that consists of a light attack, which can be comboed together, and a heavy attack, which is ranged for most of the chracters, and each of the robots represents a different "giant fighting robot" genre from Japanese culture. In that sense, the game is a sort of VS game for fans of giant robot media. The game also features finishing moves that are similar to Mortal Kombat's trademarked Fatalities, except that they can be called up in the final round of combat when an opponent has very little health left. The moves are avoidable, however, and can only be attempted once, making them more like Guilty Gear's DESTRUCTION moves. In addition, the game has a block button, and each mech has an armor rating. As blocking is used more, the armor meter decreases, until it eventually depletes and blocking now merely reduces damage instead of stopping it altogether. This promotes a more aggressive play style as a mech with destroyed armor will take more damage with or without a block. The game is also unique for fighting games, especially at the time, because each character had a specific story mode that brought them not only into battle against most of the other mechs from the game, as well as three "boss" mechs at the end, but many stories had branching paths that would be triggered if certain conditions were met during a given battle.
Two mechs enter, one mech survives. The combat in Tech Romancer is simple on the surface, but can become quite complex with the addition of guard breaks, super moves, dashes, and 3D evasion. There are even items that will be revealed when prominent buildings are destroyed. These can give the effects of healing, powering up, or activating Hero Mode, in which the mech will have access to new moves and abilities for a short time.
Tech Romancer, as mentioned above, features characters from the Giant Fighting Robot genre of Japanese television and movies.
Armour Knight G (Grand) Kaiser: A superhero type mech in the same vein as Mazinger Z, G. Kaiser attacks using rocket punches, bombs and a chest mounted laser beam. It is piloted by the hot-headed Junpei Todoroki (voiced by Kōichi Tōchika) who seeks justice for the death of his family.
Super Defense Armour Dixen: Representing the "real robot" mech type made famous by the numerous Gundam series and piloted either by Nakato Farland (voiced by Shigeru Nakahara) or Halma Flockheart (voiced by Yoshino Takamori) (only matters in Story Mode), Dixen is an extremely versatile mech that can switch between a beam rifle and a bazooka. It is also armed with a shoulder-mounted beam cannon, grenades and three remote-controlled beam guns to meet many different situations. Also has a variant piloted by Shadow Red.
Pulsion: A "living robot" that mimics the likes of Ultraman and his many spin-offs, Pulsion is not piloted, but actually IS either the male Kai (voiced by Takehito Koyasu) or female Kei (voiced by Miki Nagasawa) (once again only mattering in the story mode) grown to massive proportions and endowed with a new form. Pulsion was originally sent to Earth by Goldibus to destroy it but wound up having his/her memory erased in a battle with Diana-17. In Hero Mode, Pulsion's fighting style changes to resemble Evangelion Unit 01 in it's Berserk Mode. A evil version of Pulsion named Dark Pulsion can also be unlocked.
Strategic Variable Fighter Rafaga: A robot that can transform from it's GERWALK and/or Soldier (mecha) mode to a jet fighter. It is heavily inspired by the VF-1 Valkyries from Super Dimensional Fortress Macross. Piloted by, ladies' man, Simon Harvard (voiced by Takehito Koyasu) who falls in love with the alien pilot Yale. A variant of Rafaga can also be unlocked that is piloted by Amuritta, Simon's more professional wingman who harbours a small crush on him.
Phantasm Unit Twinzam V: A super robot, based on the combining robot genre of anime like Getter Robo, that is actually made up of two aircraft that combine together and can switch between two forms. It is piloted by 10-year-old Daichi Yumeno (voiced by Rica Matsumoto) and his 11-year-old sister Sora (voiced by Mayumi Iizuka) who enter this world through shared dreams and become trapped by Arekshim, pilot of Gamda.
The Messenger of Beauty and Justice Diana-17: An agile female-styled fighting mecha that is piloted by Reika Amamiya (voiced by Michiko Neya), a student at a girls' academy and secret super hero, who is initially the first person to learn of Goldibus' invasion plot. She spends the game trying to rally the other heroes.
Heavy Armour Tank Wise Duck: A heavily armed, slow moving, bipedal tank who bears a resemblance to Metal Gear Solid's Metal Gear Rex. It is piloted by an entire crew consisting of Gonzales (Commander) (voiced by Daisuke Gōri), Arvin (Combat) (voiced by Shigeri Nakahara), Ricky (Gunner) (voiced by Kōichi Tōchika), Thomas (Pilot) (voiced by Takehito Koyasu) and Herman (Sonar/Communications) (voiced by Shūichi Ikeda). Wise duck also has a variant piloted by Shadow Red.
Magical Patched Robot Bolon: A robot made out of parts of several buildings. It is the creation of Pollialm "Pollin" De Pollintein (voiced by Satomi Koorogi), a magical girl who appears only 8 years old, though she can age herself to be about 17. She has a crush on Junpei and is also actually the daughter of Goldibus.
Mariou Shogun Gourai: A massive red, Samurai-style mecha, that fights using a giant sword. Piloted by Shadow Red who, at first seems to be a general in Goldibus' army, has an agenda of his own. He is somehow connected to to Junpei and is seen as Nakato's rival during his story. His appearance and story is inspired by Char Aznable (both voiced by Shuichi Ikeda).
Variant Armour Blodia II Custom: An unlockable robot piloted by Jin Saotome (voiced by Yūji Ueda). They are the main characters from Armored Warriors and Cyberbots: Fullmetal Madness.
Quvearl: An Octopus-like bio-contruct that is controlled by the female alien Yale.
Gamda: A massive kaijuu-like stone golem controlled by Arekshim (voiced by Ryūsei Nakao), an alien ruler who has allied himself with Goldibus. He has an Egyptian theme.
Goldibus: The main antagonist of the game. He has two forms that must both be defeated to beat the game.Voiced by Chikao Ōtsuka.