Tony Hawk's Pro Skater - Did You Know Gaming? Feat. Brutalmoose
Accessing the arcade cabinet used for a specific goal on the Skatetopia level reveals a hidden message written out in the high score initials.

The message, reading, "TEN HARDCORE YEARS KICKING YOUR ASS", which is a reference to Neversoft Studios developing the Tony Hawk game franchise for ten years.
Contributed by Regen-33
Kenny the Koala, the mascot from the zoo level in Tony Hawk's Pro Skater 4, appears as a statue in the Australia level of the game.
Contributed by DeerBoarDude
The internet icon "Star Wars Kid" appears as an easter egg Spoiler:in Boston, at first is just sits watching the television in front of him but on command he does his signature "moves".
Contributed by mrlenny94