Phineas Flynn (2nd Dimension)

Phineas Flynn is a boy in the Flynn-Fletcher family, and the 2nd Dimension counterpart of Phineas Flynn. Stuck in an area which is ruled by Dr. Heinz Doofenshmirtz, he has grown up without summer vacation and has never heard of it.

Early life
Phineas's early years were presumably the same as those of his 1st Dimension counterpart: his mother Linda met and fell in love with Lawrence Fletcher, to whom she later married, and he and his sister, Candace, gained Lawrence's son Ferb as a stepbrother. At least five years prior to Across the 2nd Dimension, Phineas and Ferb bought Perry, who apparently was a secret agent (it is never brought up). Somehow, Perry was defeated and captured by Dr. Doofenshmirtz without Phineas' knowledge and turned into the Platyborg, which commanded an army of Norm bots to invade The Tri-State Area and conquer it. Now forced to live under Doofenshmirtz's tyrannical reign, Phineas spent the recent years wearing Dooferals and playing Doofopoly with Ferb. At some point, Candace founded The Resistance, an organization bent on ending Doofenshmirtz's rule once and for all, but forbade Phineas or Ferb from joining it out of concern for their safety.

Present life
Phineas and Ferb meet their 1st Dimension counterparts, with the former believing that they are being replaced with duplicates at first. He shares an emotional hug with Perry-1, initially believing he is his Perry, before he tells Phineas-1 of the nonexistence of summer in the 2nd Dimension. After Perry-1 departs, the four all decide to go to the house of Isabella for help, during which they are joined by Buford. The five then arrive at the Resistance headquarters via chute, and he, Ferb, and their 1st Dimension selves find out that Candace is the Resistance's leader.

Candace agrees to help Phineas-1, Ferb-1, and a recently-arrived Candace-1 retrieve a captured Perry-1, but tells him and Ferb to stay behind. However, they stow away in the mine carts used by the Resistance to get to Doofenshmirtz Evil Incorporated. When the group manages to rescue Perry-1 and get pursued by Norm bots, Candace is forced to separate the mine cart containing the 1st Dimension characters, resulting in their capture; Phineas protests against this, but he is overridden.

Later managing to get recruited into the Resistance along with Ferb, Phineas arrives at DEI to rescue Candace, who was captured after aiding the 1st Dimension characters. She initially disapproves of her brothers' decisions, but after seeing they can handle themselves, she changes her mind and the three share a loving hug.

Phineas is later among the Resistance members that congratulate the 1st Dimension characters for defeating Doofenshmirtz. He is also reunited with Perry, whose evil was "fried out of him" after a climactic showdown with Perry-1, and he returns to his home dimension with his pet ("Phineas and Ferb The Movie: Across the 2nd Dimension").

Personality
Phineas is presumed to be an optimist, like his 1st Dimension counterpart, though this side of him isn't shown in the film. Speaking of which, he is depicted in the movie as having a need to join The Resistance's movement of overthrowing Doofenshmirtz, only for him and Ferb to be rebuffed by Candace. He also displays a caring attitude, which is usually aimed towards the 1st Dimension characters in the film, as he showed reluctance at allowing Candace to separate their mine cart from theirs, which would result in their capture at the hands of the Norm bots.

Physical Appearance
Phineas is physically identical to his 1st Dimension counterpart, except that he is paler, has his hair cut military-style, and wears a white shirt and Dooferalls. As a Resistance member, he wears a dark-brown or light-black shirt with a large black collar, black shorts, black boots, dark-gray gloves, a silver shoulder-pad with a strap, and a headband that holds what appears to be a laser weapon and/or communications device.

Ferb Fletcher
He sees Ferb not only as a stepbrother, but a best friend, identically to how the 1st Dimension Phineas views his own Ferb. They would presumably spend all day playing Doofopoly.

Candace Flynn
He loves Candace very much and appreciates her care and concern towards him and Ferb. However, he is willing to disobey Candace's orders to not join the fight against Doofenshmirtz and would protest this matter to his sister.

Perry the Platypus
Perry was once Phineas and Ferb's pet platypus, until he was defeated and captured by Doofenshmirtz and turned into the Platyborg. Phineas expressed extreme concern for Perry and misses him a lot, even hugging the 1st Dimension Perry for a time as he resembled his Perry. When Perry's evil was "fried" out of him in the 1st Dimension, he greeted his owners and Phineas was overjoyed at his pet platypus' return. He said that Perry's new partially robotic body "makes him extra cool!"

Background Information

 * Website Summary:
 * Being a conformist, Phineas wouldn't dream of breaking the mold that Doofenshmirtz has created for everyone in the 2nd Dimension. Sadly, years ago his pet platypus Perry went missing and he's never heard of summer vacation. He likes to stay out of trouble and play Doofopoly while wearing his Dooferalls with his brother Ferb.
 * At the end of the video game, Phineas tells Ferb that they are going to build "the best rollercoaster ever", a statement that is meant to be a tie-in to the show's pilot episode.