Badass Bookworm: His peanut butter and jelly sandwich gun, the memory scanner, fixing the time machine, eventually building Carl the robot, and the other numerous inventions he's done in the future with the Robinson Industries.
Future Badass: What he becomes in the future as Cornelius. Many of the inventions he's built has really helped people. Lewis even learns he has his own invention company.
Bungling Inventor -> Gadgeteer Genius: Many of the inventions he's made has not always worked, i.e. the PB&J gun. In the climax, with a newly regained confidence, Lewis manges to fix the time machine, as well as create the future inventions that are used in the future.
Child Prodigy: He is ridiculously intelligent. Obviously he develops into a Teen Genius, as he ends up graduating from college at fourteen.
My Future Self and Me: Lewis and Cornelius. Confused? Cornelius is the name Lewis gives himself in the future.
Missing Mom: He constantly obsesses about her and once he's introduced to the concept of time-travel, desperately wants to meet her. When he finally goes back in time to where he was left as a Doorstop Baby, he decides to leave his biological mother be after seeing her cradling the baby she's about to give up.
My Greatest Failure: After Goob explains why he "turned evil", Lewis starts seeing his semi-abusive behavior of young Goob as this and fixes it by waking Goob up in time for him to win at an important baseball game.
Science Hero: The hero who has been making his own inventions probably before he was 12.
Self-Made Man: Thanks to the memory scanner, he was able to show what he could do. Even owning his own company and building the inventions in them.Though having a scientist for an adopted mom probably helped matters.
"Bowler Hat Guy" MikeYagoobian and DOR-15
"Everyone will tell you to let it go and move on, but don't! Instead, let it fester and boil inside of you! Take these feelings and lock them away. Let them fuel your actions. Let hate be your ally, and you will be capable of wonderfully horrid things."
Freudian Excuse Mike blamed Lewis for making him miss the winning ball for his team, which got him beaten up. The loss took a toll on him that he never got adopted and stayed in the orphanage until he hit his thirties.
Green-Eyed Monster: The director's commentary states that jealousy of Cornelius Robinson is Bowler Hat Guy's entire motivation for his villainy.
Harmless Villain: Until he meets Doris, and even then he is hopelessly incompetent at being evil.
Hypercompetent Sidekick: Doris appears to be this to Bowler Hat Guy for most of the movie. The truth is a lot more sinister: she's actually the one who's manipulating him in her own plan for world domination.
Obsessed Are the Listmakers: Bowler Hat Guy loves checklists and is often seen ticking off items in his, such as "Steal time machine", "Ruin science fair", and "Get that [comic book swearing symbols] boy".
Psychopathic Manchild: Bowler Hat Guy never let one childhood trauma go and thus kept a child-like mentality.
Straw Loser: Bowler Hat Guy doesn't shower, doesn't even bother to think his evil plans through, and initially couldn't think of any way of revenge more effective than throwing eggs and toilet paper at the Robinson Industries sign.
Unwitting Pawn: Bowler Hat Guy to Doris. Turns out Doris was only using Bowler Hat Guy's hatred for Lewis to trick him into getting the time machine, so he could he use it to steal one of Lewis's inventions and make a lot of money. Then, Bowler Guy would use the money to build more Dorises. Then, the real Doris would have her clones enslave the humans.
Woobie, Destroyer of Worlds: When his motivation is revealed. Goob, who finally snaps when his life goes downhill due to Lewis unintentionally causing him to miss the ball. Even if he's not intending for the world to hit the Bad Future that The Man Behind the Man is trying for, the fact is, he is still looking to deliberately ruin the man responsible for much of the awesome tech that the future runs on, thereby making a future that's much less advanced (if not quite a Crapsack World).
Badass: He escaped from a T-Rex just using a meatball shooter!
Badass Adorable: His facial expressions and being able to take down a T-Rex.
Ret Gone: near the end of the film. He turns out to be Lewis's son, and since Lewis gave the Bowler Hat Guy the directions he needed to work the time machine, reality was altered. Lewis never met Franny and so Wilbur was never born. Don't worry, he gets better.
Rousing Speech: Part of said plan is to give Lewis one of these, so he will fix the memory scanner turns out Wilbur is Lewis's future son.
Time Police: Initially pretends to be one of these to help Lewis stay alert for the Bowler Hat Guy.
False Teeth Tomfoolery: When Lewis first meets Grandpa Bud, he is hunting for his false teeth, in quintessential Robinson style.
Fiery Redhead: Petunias, her "daughter" Tallulah, and her "son" Laszlo. They show their fiery nature when Petunia' s children were arguing while painting the house. A few minutes Petunia slaps her husband.
Genki Girls: All of the female members who have the Robinson eccentricity.
Henpecked Husband: Uncle Fritz. Aunt Petunia berates and smacks him around...which is strange since she looks like just a hand puppet.