Mickeyjunk Mountain, an area built out of old Mickey merchandise, contains cartridges of old Mickey games on the NES and SNES. Its theme also contains a brief segment of The Mickey Mouse Club theme.
Not only is "Petetronic" wearing armor that glows with Tron Lines, he throws a homing Deadly Disc from his back, and summons rotating energy shields to protect him, all inside a presumably computerized arena where floor tiles disappear when struck.
He's wearing Sark's armor, specifically. Beating him with Paint slowly turn's it into Tron's suit. The whole fight is a reference to the battles with giant Sark and the MCP.
Petetronic has somewhat of a Zelda-ish feel, as he throws his Disc at you, and Mickey makes it fly back in a sort of Ocarina of Time/Wind Waker/Twilight Princess + Mickey Mouse boss.
A piece of concept art in the game revealed him to have more of a Treasure Planet-y feel, making him look more like Long John Silver.
Dark Beauty Castle is the Wasteland's counterpart to the Disneyland Paris version of Sleeping Beauty Castle, complete with a somber reendition of "Once Upon A Dream" for its Leitmotif. It's also loaded with fireworks.
The castles at the Disney theme parks the 2D transition level based off Sleeping Beauty resemble one of the old doll dioramas that were used to tell the story of Sleeping Beauty in the old castle walk-through.
One of the statues in the very first room in Dark Beauty Castle IS the Beast himself, holding a three-pronged candle. We all know who this is supposed to be.
Most of the Wasteland is built on forgotten or existing Disney Theme Parks rides. Divided by area:
Gremlin Village: Dumbo ride, Aladdin's Flying Carpets, It's A Small World.
Tomorrow City: The Sky-Ride, the People Movers, Space Mountain, Moonliner Rocket and Not-ilus. The Autopia is added for the sequel.
Tortooga: Skull Island, the Swiss Family Robinson treehouse, the Enchanted Tiki Room, the Pirates of the Carribean ride (complete with burning buildings in an area that boats pass through), Adventureland.
Mean Street: The cinema (showing Steamboat Oswald), souvenir shop, penny-arcade, and ice-cream parlour all exist in real-life Main Street.
Ostown: Donald's Tug-Boat and Mickey's House.
Lonesome Manor: The Haunted Mansion.
New Orleans Square (under the name Bog Easy)
Disney Gulch (Frontierland, particularly Mine Train Thru Nature's Wonderland)
Fort Wasteland (Tom Sawyer Island)
Rainbow Caverns (The Rainbow Caverns portion of the Mine Train, mashed together with elements of Snow White)
Several characters from Thru The Mirror appear, including Mickey's phone, the radio and the card soldiers.
In the library of Lonesome Manor, the statue near the staircase is Simba.
When filling in paintings in Dark Beauty Castle near the end of the game, you find a small paintable square on the wall. Paint it in, and it becomes the Beast's portrait in human form from the West Wing, complete with claw marks through the center.
There are even references to Kingdom Hearts! Casey's key you have to get near the start of the game? It's design is very similar to Kairi's keyblade. Mickey getting his heart stolen sounds familiar as well. Some of the blotlings act very similar to heartlesses.
In the sequel, the new versions of the Travel levels are called Dahl Engineering Corridors.
Power of Illusion features references to Disney's gaming history. A sketch to summon Scrooge McDuck has him using his pogo cane and a Goofy sketch has him using his spin attack from the Kingdom Hearts games.