Down the Hatch (2x05)
Adventure Thru Inner Duck
The song Donald sings over the end credits of Down the Hatch is Miracles from Molecules. The song was written by the Sherman Brothers (of small world and Mary Poppins fame) for the Disneyland attraction Adventure Thru Inner Space, in which guests shrunk down to subatomic size - an appropriate choice for this particular short. The attraction operated from 1967 to 1985.
The lyrics to the verse Donald sings are as follows (he omits the bracketed lines from the original):
Miracles drom molecules Are dawning every day Discoveries for happiness In a fabulous array A never-ending search is on [By men who dare And plan] [Making modern miracles] From molecules for man
The original song can be heard on YouTube.
In addition to the use of the attraction's song, Mickey also refers to it within the short's dialogue:
"Wow, a shrink ray?! With that you could explore INNER SPACE!"
The concept of shrinking down and exploring the inner workings of a body (a la Fantastic Voyage) is not new territory for Disney. It was also used as the concept for a now-defunct motion simulator ride in EPCOT called Body Wars that operated from 1989 to 2007. The ride was located in the also defunct Wonders of Life pavilion in Future World. The physical ride was very similar to the still-extant Star Tours (in fact, it used the exact same ride system).
The scene from the short pictured above, in which Goofy and Mickey travel through a 3d-animated esophagus, may be a deliberate nod to this attraction.
Space Walkies (2x10)
At the end of Space Walkies, when Mickey and Pluto return to Earth, they seem to land in Tomorrowland.
Space Mountain can be seen in the background, as well as a PeopleMover or monorail track.
The look of the spacecraft in the short is borrowed from the exterior of the (nearly) opening-day Disneyland attraction Rocket to the Moon (later revamped as Mission to Mars), pictured below.
The letters TVA on the side of the spacecraft in the short have a double meaning. They evoke the TWA sponsorship of the original attraction, as well as serve as a reference to Disney Television Animation, commonly shortened to DTVA or TVA.1 DTVA is the production company responsible for the new shorts.
Mickey Monkey (2x11)
Mickey Monkey starts in a treehouse and primarily takes place on a river cruise through a jungle. If that sounds familiar, it's because these locales were inspired by the Adventureland sections of Disneyland-style parks.
The boat in the short is modeled on vintage Disneyland Jungle Cruise boats. The treehouse at the beginning of the short may be inspired by the Swiss Family Treehouse (later Tarzan's Treehouse in Disneyland; the Swiss Family theme remains in Walt Disney World), also found in Adventureland.
The color palette may even be specifically inspired by vintage posters such as the one below.