Alternate Character Interpretation: The entire series is an Evil Plan by the Bunyips to get TY powerful enough to wipe out the Quinkan, leaving no force powerful enough to stop the Bunyips. Hey, they're not good guys in Aussie folklore, so their benevolence in-game is more than a little off-putting.
Annoying Video Game Helper: An interesting case for Lenny the lyrebird; he's not as helpful as you'd want... until you start doing the opposite of what he says. He later gets a job telling stories to kids in daycare, which are actually all true, being recountings of boss fights from the first game.
In the second game, Boss Cass' final form is... himself. No fancy mechs (on his part), no special effects, just the one cassowary. Though hitting him with the Shadow Bunyip's Frickin' Laser Beams is a guilty pleasure...
The Quinking in the third game starts off as a powerful and hard to predict Ty clone, but once pushed will turn into a giant dinosaur-like creature which is far easier to predict and is overall much easier than his first form.
Also from the second game is the second boss Buster, a giant collection of nanobots that look like spiders with red eyes that form several things such as a sphere or humanoid being, both of which are freaking gigantic. His bizarre cybernetic musical theme accentuates how horrifying he is.
Scrappy Mechanic: Kart racing was a fun distraction to the main quest that people enjoyed... Until it was made mandatory in three with absurd conditions that just make doing these missions a chore.
Sidetracked by the Gold Saucer: Kart racing! It can either be done from the main story mode (where it's theoretically a useful way to get opals, but we know you're just doing it for fun) or as an option from the main menu (so you can skip the middleman, play any character you want, and even go on a grand tour of all the courses in the game).
The Scrappy: Shazza, Lenny the Lyrebird, the frill lizard and goanna in charge of the Bush Rescue Training Program in 2 and Dennis.
They Changed It, Now It Sucks: The voice acting changing between games one, two, and three, and the excess of mech or Gunyip levels in game three.