Ratchet & Clank: Size Matters

The first game of the Ratchet and Clank series on the PSP, and then ported to the PlayStation 2.

It revolves around a shrinking device, as well as Captain Qwark trying to find his lost parents.

Tropes used in Ratchet & Clank: Size Matters include:

Barefoot Cartoon Animal: Ratchet, as he wears his outfit from the first game. He can use shoes later in the game.
Continuity Nod: Several in Ratchet's dreamscape, like Clank's apartment in Bogon and larger form (see Lost Forever). Then there's this exchange, which mirrors a conversation from the original game.

Ratchet: There she is! Let's get her!
Clank: Ratchet, do you notice anything... unusual about Luna?
Ratchet: Well, she does seem to have an unusually large door coming out of the back of her head.
Clank: And why do you think that is?
Ratchet: She's... uh... a robot?

Fantastic Voyage: Ratchet goes inside Clank to reboot him after he is attacked by Technomites.
Game Breaking Bug: On your second or third playthrough (PSP version), the Omniwrench all of a sudden stops damaging 90% of your enemies. This will never go away, on every subsequent playthrough.
Incredible Shrinking Man
Lost Forever: The "Friends Don't Hurt Friends" skill point is lost until a New Game+ if you took damage during the Giant Clank "fight" and beat the "battle", as it doesn't reappear after you win.
New Game+: Of course. But to get everything, you have to go through the game three times.
Walking Shirtless Scene: Ratchet, as he wears his outfit from the first game. He can use a shirt later in the game.