You can just see the conga line of disappointments for Guy. His past failures have given him severe low confidence in himself that he he feels inadequate compared to the other inventors, yet he's still determined to give it one last try. Then just as it seems he's about to have all his dreams come true, his invention goes wrong and explodes. Then his bus pulls away from him just 3 seconds after he buys a ticket, leaving him behind with a useless ticket. He goes to a diner where everyone makes fun of his food choice "the sad man" special. Then just to have the universe rub it in, all the successful inventors come into the diner to celebrate.
And just before that he was looking at a "watch paint dry" job. You can really tell that all his dreams have been crushed at this point.
Later Guy has to make a choice; while he loves to invent, "stuff blowing up is a valid complaint." As he's thinking his choice over, the other inventors are celebrating in a pool outside of his room and are mocking him when he tries to shut them out. This hurts him so much that gives up on his dream and throws his briefcase into the fireplace.
E.B.'s life is sad too as her overprotective mother won't allow her to have toys, play with her friends, and only allows a certain amount of whimsy. Her mom even gets her a "friendship" bracelet that works more like a handcuff.
Despite being so happy, we see the first glimpse of how lonely Sam is when he hangs out in the diner all day and when it's closing it shown that he's invited a lot of people to where he's staying as he's that desperate for company. He's given Donna, the waitress, his address and number seven times now (In a non-creepy way). When she reminds him of this, he wistfully smiles and sadly leaves.
How sad all the animals look as they're trapped on Snerz's wall
Car
Even though the Chickeraffe doesn't want to hurt him it is causing a LOT of destruction, all of which Guy realizes is going to be on his head. You just see the despair as he realizes this. He tries to save the room and stop the creature, but we all know it's hopeless.
Small touch, but we see how much Sam wants visitors as the signs on lawns are practically begging people to come.
He gets what he thinks is the Chickeraffe to his home and is excited to give many hugs to "his new friend," only to discover he has the wrong case.
When Sam inadvertently rubs it in that Guy is giving up on his dream to be a paint watcher, Guy immediately demands to be let out. Sam is saddened by this as he was clearly looking forward to Guy's company. Sam apologizes for not being excited about the paint job, but defends that he thinks Guy is destined for great things. Guy, however, is so broken at this point that he doesn't believe it.
Seeing how desperate Sam is to gain a friend in Guy and Guy rejecting his offers may be this for a few. Sam looks so dejected when he finally gives up and drives away.
E.B. gets excited at the idea of having fun for two seconds before her mom tells her she'll only be able to see these things from a safe distance.
When Guy is walking he clearly needs help and despite feeling embarrassed at seeing Michellee — who witnessed his failure — he still asks for help. Michellee however just ignores him and keeps driving at her snail's pace. She then starts to insult him over and over again, despite Guy not having done a single thing to her, and leaves him in the dust.
Train
The BADGUYS' car crushes the home of an innocent fish family and leaves them homeless. It's Played for Laughs, but it stops being as funny when the audience sees them later on surrounded by rescue vehicles and doing a headcount to make sure everyone got out in time.
Guy's briefcase was in the car. Despite giving up his dream, he is sadden by the loss. When Sam inquires about the invention, Guy states that it was a piece of junk and he's glad it's gone. He's clearly lying.
E.B. is happy when she sees the play room on the train, only to have her mom use the bracelet to literally drag her away and through the fun stuff.
When E.B., Michellee, Sam, and Guy are all in the same dinning car Guy is embarrassed to be seen by Michellee who insults him once more upon recognizing him. Guy doesn't even respond to defend himself.
After being forced to eat with the girls Guy goes an explanation about how trying new things may be bad and lead to worst things and mockery. Not hard to see figure out how he came to that conclusion after his failures.
When Guy finds out E.B. knows about the chickeraffe Guy is worried that Michellee will find out he lied.
Guy is so upset about this that he gets fed up at Sam for making him a felon, almost drowning him, and stealing his wallet three times, and leaves a sad Sam and Mr. Jenkins behind.
Fox
Mr. Jenkins being sad about Guy being gone. Thankfully it doesn't last long.
Michellee is disappointed when Guy says they can't eat together. Of course then the Chickeraffe shows itself and the moment is replaced with a betrayed and hurt moment of being lied to.
Guy tries to go after her, but then the BADGUYS show up, forcing him and Sam to flee.
Dark
The Fox really loves his chicken crush Sandra, but loves eggs as well. The love of these two things really tear him up. His last words to Sam and Guy as they flee is not to tell Sandra.
Though E.B. starts to have fun drawing her mother ruins it by being critical and taking over the drawing. E.B. decides to draw else where, leaving her mother alone.
Potentially sadder in retrospect after it's revealed Michellee was an amazing artist before leaving it behind to raise E.B. What at first seemed overly critical was likely Michellee's excitement that she could her daughter could bond over their passion for art.
Guy invents something to start a fire, but throws it down when it seems not to work.
Guy tells Sam the stories of his failures. They all seemed to work and everyone was happy, in the end they all exploded and until he lost all hope and his heart said nope.
After Guy tells his story, Jenkins remembers his own; he lived on an island with his mother who he loved with all his heart until a hunter came and tore them apart.
Blink and you'll miss it, but after Jenkins has his own flashback, Sam can be seen brushing a tear away. Unless Sam is able to read animals' minds (highly unlikely), he was most likely cryingabout his own life.
Box
Doubles as an awesome moment: Guy completely chews out Sam for breaking the rules and getting away with it, and his rage boils over as he explains that nothing goes right for him no matter what he does.
Mouse
After Sam evades the police, he goes up to the water tower and sees Guy, who he thinks is waving to him. In actual fact, Guy was calling a taxi, and when he sees this, Sam is absolutely crushed.
House
Guy and Sam open up to each other about their insecurities and we learn that Sam's mother abandoned him when he was young and all he can remember is the taste of the breakfast she made for him.
Sam, after looking at Guys family huddled together on the couch, sadly calls Snerz and assures him he'll get Mr. Jenkins to him on time. Even the Narrator is utterly shocked at Sam's true colors.
Boat
Sam's constant guilt for his goal to turn in Mr. Jenkins to Snerz. It shows that he's not straight up evil as others would believe.
There
All Guy can do after learning the truth about Sam is sag in despair with his head on the table, surrounded by images of Sam's false identities.
The fight Sam has with Guy. Guy is naturally hurt and betrayed by finding out that Sam is actually a scam artist who wanted to sell Mr. Jenkins to Snerz, and eventually his anger reaches the Rage Breaking Point, where he tells Sam that he doesn't, "fit anyone, NOT EVEN YOUR OWN MOTHER." The look on Sam's face afterwards pretty much says it all.
After the aforementioned fight, it looks like Guy has finally given up, and proceeds to go to his paint-watching job.
Anywhere
E.B. feels just as betrayed as Guy when she sees Sam apparently selling Mr. Jenkins to Snerz, and claiming Guy, her mother and herself were just patsies.
And then Michellee sees Snerz's wall of animals with "Mr. Jenkins" at the top and, believing Guy is responsible, tells him he's lost her last shred of trust. Fortunately it doesn't last long.
Sam, Guy, Michellee, and E.B. giving Mr. Jenkins a tearful group hug before they send him home.
Pam's coldness towards Sam all throughout the episode. At Port Ta-Gong, she reveals she had to leave to keep Sam safe but it's still pretty tough to watch her try and push her son away.
Goldenguy
Pam has to leave Sam behind again. It's easy to see how hard it is for both mother and son to have to split up again.
Guyfall
Guy lets Looka, whom E.B. has a crush on, to get captured by the Yookian soldiers, which causes a huge strife between Guy and E.B., with E.B. being really hostile and angry at Guy for the entire episode. It's clearly difficult for both of them, as Guy just wants to keep E.B. safe but in turn disregards E.B.'s actual wishes, much like Michellee in Season 1.
When Guy reveals to E.B. that her mother is pregnant, she coldly tells him that he's going to be a terrible father to the baby, because in her eyes, that's all he's been to her.
Guy starts feeling suspicious about Pam because of her somewhat vague behavior and eventually confronts Sam about it, telling him how he's worried that Pam might just leave him just like she did when he was a child. Sam becomes distraught over the idea, but eventually decides to stick by her.
The Sam Who Came in From The Cold
Pam revealing why she had to leave Sam at the orphanage - as a secret agent, she was constantly attacked by enemies, which put Sam, who was at the time a toddler, in danger. She really didn't want to abandon Sam, but felt like she had no other choice because she didn't want something bad to happen to him because of her. Patricia Clarkson's acting really sells how hard it was for her to make that choice, with her sounding visibly chocked up the entire time she's telling the story.
Sam becoming disillusioned with his mother when she insists that they stay away from Yookia and Zookia when they are about to go to war, since his friends are still in Zookia.
