When Dinky Winks first appears, the rollercoaster behind him is the Titan; the tallest and fastest rollercoaster in Texas. Through the park, you can also see the Oil Derrick, the Dive Bomber Alley, the Batman, the Texas Chouteout, the Wildcatter, Mr. Freeze, the Shockwave and the Flashback.
There are two 'Lord of the Rings" references in the movie. The first, when Juni picks up a necklace and says "One necklace to rule them all"; and the second, the outtake of the same clip during the credits where instead Juni says "My precious".
All the rides in this movie in the first scene that are mentioned by name are computer animated. The Whippersnapper is the Oil Derrick at Six Flags Over Texas, with Computer Animated movement, the NerveWracker was the Dive Bomber Alley with Computer Animated movement, the Vomiter and Juggler were both completely animated.
When Gary and Gerti Giggles are hanging onto the cliff; Gary says the quote to Juni; "Thanks for the update, carrot top!". This is a reference to comedian Carrot Top; who is notorious for his wild and curly red hair.
The trivia items below may give away important plot points.
Oscar nominated director, Richard Linklater (Boyhood (2014), Slacker (1990), etc.) and his daughter, Lorelei Linklater have a cameo in the movie. At the OSS banquet, Lorelei and Richard are seen when all the adult operatives have been drugged.