!!Nathan “Rad” Spencer
* [[ArtificialLimbs Artificial Arm]]
* BadassMoustache: Grows a thick, American police chief-worthy manly moustache in ''Rearmed 2''.
* EmpoweredBadassNormal: In addition to his arm, Spencer has a number of [[RequiredSecondaryPowers secondary bionic improvements]] that, for example, provide armor, weaponize his adrenaline, allow him to jump superhuman heights and fall hundreds of feet without injury, and more. He looks mostly human, but he is far from it.
* OneManArmy: In the NES version, he's the sole representative of the "FF" Double Force, wielding a Bionic Arm as a unique grapple wire. Expanded storylines explain this as him being an [[SuperSoldier experimental soldier]] supplied by the TASC bionics division.
** Averted somewhat in ''Chain of Command'' and ''Rearmed 2''; TASC has a period where their bionic technology is in great demand following the Imperial Incident, leading to Spencer training the next generation of bionic commandos as a Major.
* RetractableWeapon: The wire part of his Bionic Arm.
* TheRightHandOfDoom: The Bionic Arm, though it originally looked rather ordinary and was covered by his clothing.
* RoleCalled: While debatable in the arcade game, he ''is'' considered the "original" Bionic Commando in-universe.
* SpellMyNameWithAnS: His name was initially translated as "[[JapaneseRanguage Ladd]] Spencer" in the NES localization.
** Officially, when Nathan Spencer originally lost his arm, he was the first person to be considered and tested on for bionic augmentation. He was therefore the most important part of the '''R'''esearch '''A'''nd '''D'''evelopment department for bionics. When he went into the field, he was humorously given the codename [[TotallyRadical Rad]] from all his time in the labs.
* SuperDrowningSkills: Spencer's bionic arm is extremely heavy, and almost completely shuts down when exposed to water. Spencer therefore cannot swim in water as his arm drags him down.
* TookALevelInJerkass: Went from a typical cocky action hero in ''Rearmed'' to a brooding, "[[Webcomic/PennyArcade I smoulder with generic rage]]" anti-hero in the 2009 game.
* YouDontLookLikeYou: The original design, ''Rearmed'', ''Chain of Command'' and ''Rearmed 2'' all at least ''seem'' like different stages of the same character - his Game Boy and 2009 / ''VideoGame/MarvelVsCapcom3'' appearances look ''entirely'' different without any explanation whatsoever.

!!Joseph “Super Joe” Gibson
* [[spoiler:BigBad]]: [[spoiler:Of the 2009 sequel]].
* [[spoiler:BigBadFriend]]
* DistressedDude: In the NES game and its Game Boy and ''Rearmed'' counterparts. This also applies to his {{expy}}, Commander Joe, in ''Bionic Commando: Elite Forces''.
* [[spoiler:FaceHeelTurn]]
* [[spoiler:TheManBehindTheMan]]
* MissionControl: He got promoted to TASC director after his rescue. According to ''Bionic Commando: Chain of Command'', his correct title is even '''Super'''visor, '''J'''oint '''O'''perations '''E'''xecutive.
* [[spoiler:RogueProtagonist]]
* [[spoiler:SuddenSequelHeelSyndrome: Besides his major role in the original ''Bionic Commando'', Joe was the player character in at least three other Capcom games back In the 1980's and 1990's. He then became the BigBad of the 2009 game.]]

!!Hal(ey)
* CompositeCharacter: The ''Rearmed'' version of this character combines the original role of the nameless helicopter pilot and a minor (but important) soldier (which the Game Boy version instead combines with Super Joe).
* GenderFlip / [[AdaptationNameChange Name Change]]: The NES character was a male soldier named Hal, which was changed to a female pilot named Haley in the ''Rearmed'' remake.
* ImDyingPleaseTakeMyMacGuffin: Or in this case, a bazooka, although we never actually see the character die in the NES version.

!!Gottfried Groeder
* BigBad: [[spoiler:Subverted]]
* DragonAscendant: Went from Generalissimo Kilt's TheDragon in ''Rearmed'' to the co-leader of [=BioReign=] in the 2009 game.
* EvilCounterpart: Depicted as this in ''Rearmed'', pitting an Imperial bionic against a FSA one.
* GiantMook: He originally appeared in the NES and Game Boy games as the "Giant Soldier" - as a possible reference to this, he grows a bit taller in size before battle in the 2009 sequel.

!!Emily Spencer
* [[spoiler:DeadAllAlong- possibly as the process of creating the bionic arm has been never been explained so if she's truly dead isn't said]]

!!Jayne Magdalene
* CutsceneBoss: In the Gardens, Joe goes into a boss arena with her and it looks like she's going to be a boss fight, but then he takes her out with one punch in a cutscene.
* FaceHeelTurn: A retroactive example; she's first seen as a [=BioReign=] terrorist in the 2009 game, then in the prequel ''Rearmed 2'' we see her back in the day as a Lieutenant and ally of Spencer's.
* FauxActionGirl
* MoralMyopia: Considers civilians to be legitimate targets and their mass murder an act of "self-defense" because of the government's (admittedly pretty evil) treatment of Bionics in the Purge. She never reconsiders this, and only helps Spencer and turns against the [=BioReign=] leader [[spoiler:Super Joe]] at the end because she felt he was just using her and the other Bionics as pawns.
* NotSoDifferent:
-->'''Spencer''': You're not a freedom fighter, you're just like me. A killer.
-->'''Mag''': Then [[StatingTheSimpleSolution why I haven't shot you yet]]?