In fact, the first episode says that he was given the personality of a "perfect adult detective", implying that he's been programmed with Gadget's personality and intellect rather than just being Gadget when he was younger.
Badass Adorable: On rare occasions when he's actually competent fighting the bad guys, Gadget Boy can be this.
Spydra: My lovely cold-proof head sack keeps me immune to the uncommon cold!
Boris: (under his breath, to camera) And me immune to her ugly face!
Butt Monkey: Chief Stromboli. Even when Gadget Boy leaves him be, the guy can't go a minute without suffering an accident. Boris the Vulture is also one, even without Spydra abusing him all the time.
Catchphrase: "Zowzers bowzers!" is Gadget Boy's version of the Inspector's traditional "wowzers!" catchphrase. He's also prone to quotingMaxwell Smart's "would you believe..." and "missed it by that much."
Creepy Twins: Mulch and Hummus, Spydra's none-too-bright henchmen.
Expy: Nearly all the characters are an expy of a main Inspector Gadget character: Stromboli is Chief Quimby, Heather is (an older) Penny, G9 is (a robotic) Brain, and Gadget Boy is... well, that's kinda obvious.
Mulch and Hummus even bear somewhat of a close resemblance to some of the recurring M.A.D. agents in Inspector Gadget.
Another episode that had the gang go back in Ancient Greece had Agent Heather go to a sauna for males so she can change and disguise herself as a man to sneak into the first Olympics. We do not see her changing, but we do hear many exclamations from the men in the sauna.
Lame Rhyme Dodge: Boris would often say one after insulting Spydra under his breath, but one notable example of Boris being the one insulted occurs in the episode "Boris for President".
Mulch: Just wait until Spydra catches up with you!
President!Boris: What was that?
Mulch: Er, I said, "I'll use catsup to do it!"
Large Ham: Spydra, who often speaks in alliterative dialogue.
Leitmotif: Spydra and Agent Heather both had their own theme music.
Mad Scientist: Myron Dabble, creator of Gadget Boy. Okay, so he's not really mad, but hey, you've got to have a pretty odd mind to go and create a small child cyborg stuffed with hoard of elecronic equipment.
Monster Mash: In the episode "Gadget-Stein", Spydra goes back to Geneva in 1816 and forces Mary Shelley to create an army of monsters that oddly all resemble Boris the Vulture. The monsters are a werewolf, a skeleton, a centaur, a fat humanoid, a cyclops satyr, a Bride of Frankenstein-esque monster, a gorilla, a mummy, a Loch Ness Monster, and even Frankenstein's Monster himself.