
Ms. Frizzle is taking her class on a field trip inside Arnold in order to teach them about the human body. After the bus shrinks and flies into Arnold's mouth, you, the player, take control of the wheel. You can use road signs to travel to adjoining organs or use the nervous system to fast travel anywhere. Each organ comes with a science experiment, a mini-game, and a number of student reports. At select locations, you can exit the bus, but mostly, you spend this adventure inside the bus. Your overall goal is to find a way out of Arnold. To do that, you need to visit all twelve available organs, and then, you can take one of three escape routes.
This is the first game in the series to be developed by Music Pen, which would go on to do the next four entries, ending with Explores the Rainforest. Human Body introduces elements that would become standard in the series, such as the "Driver's License" feature, the ability to visit the back of the bus, and unique mini-games for different locations.
This game provides examples of:
- Acceptable Breaks from Reality: The game has short segments with the producer informing the player about what was fudged to make the story work, which can be accessed from the classroom. Much of it is lifted directly from the original book's closing pages, which serve the same purpose.
- Adaptation Amalgamation: Similar to Solar System, this game combines elements of the Inside the Human Body book and the TV series episode "For Lunch."
- From the book:
- Arnold is snacking at a picnic table when the bus enters him, and he's left to walk around the neighborhood while the class is inside his body.
- The focus is not limited to the digestive system, and you can visit four locations exclusive to the book version: the heart, the lungs, the brain, and the nose.note
- Some of the student reports are taken nearly verbatim from the student reports in the book.
- In one of the three endings, Arnold sneezes the bus out into the school parking lot, which is how the book ends. The other two endings still feature the bus flying out of Arnold and landing in the school parking lot.
- The producer's comments are mostly taken from the book's fact-checking section.
- From the TV episode:
- The bus has three transformed states, two of which are a submarine and traction vehicle that resemble its forms in the episode.
- The class knows they went inside Arnold.
- The kids wear their regular outfits instead of the scrubs they wear in the book.
- The bus has a monitor that shows Arnold and where the bus is in his body.
- You can go scuba diving in the small intestine.
- You can visit the large intestine, which is not visited in the book due to the bus leaving the small intestine through the villi.
- From the book:
- Adaptation Expansion: You can travel to three organs that were not visited in either the original book or its TV adaptation: the liver, the kidneys, and the skin.note
- Adaptation Explanation Extrication: A couple of the producer's comments only make sense for the book's version of events:
- He notes that if the class didn't go inside a real human body, the story would have just been about them visiting a science museum. In the book, the class was originally heading to a science museum when they got detoured with the trip inside Arnold. In the game, however, it seems like traveling into Arnold was always the plan, and no one except the producer ever mentions a science museum.
- The producer says that Ms. Frizzle probably knew where Arnold was the whole time. This is a continuation of the book's big joke that the class never realizes they went inside Arnold. But in the game, the kids are fully aware that they're inside Arnold, and you can even see exactly where he is on the Arnold Vision screen.
- Adapted Out:
- Like in the book, Arnold is left behind at a picnic table and has to find his way back to school. However, the game doesn't include the red bird that shows up to accompany Arnold in the book.
- At one point in the book, the class visits Arnold's leg muscles, which is the only location from the book to not be featured in the game.note
- Anthropomorphized Anatomy: The game leans into this, contributing to its surreal weirdness. You click on road signs to travel to different body parts, and the nervous system is described as "the expressway." When you click on them, white blood cells turn into police cars, and platelets turn into ambulances. The Kid'n' Around mini-game portrays the kidneys as a car wash. The producer acknowledges the use of this trope, calling it "artistic license."
- Anuscape Plan: Pointedly averted. There are three ways you can exit Arnold's body, and this isn't one of them.
- Artistic Licence – Anatomy:
- The nasal cavity is portrayed as one big, hollowed space with the nostrils placed together, when it should be divided into two passageways.
- Arnold is shown to have rather dense nasal hair, but he shouldn't grow them in until he's an adult.
- Bag of Holding: Dorothy Ann's bookbag contains a seemingly endless assortment of wacky items.
- Big Entrance: Ms. Frizzle enters the classroom in a volcanic explosion. Perhaps a more fitting entrance for the Inside the Earth game, but she does it here regardless.
- The Computer Shall Taunt You: When you quit the game or manage to leave Arnold through the three exit points, Liz will check off all the locations you visited during your playthrough. But if you quit the game before even entering Arnold, Liz will simply duck in and out before saying, "Did you ever think of clicking on the bus?"
- Covers Always Lie: The cover art shows Arnold inside the bus, despite the fact that they are exploring inside of him. It also shows the kids wearing their scrubs outfits from the book, which are not included in the game.
- Digital Pinball Tables: The heart's mini-game is Ticker Ball, a very simple pinball setup with a wall down the middle that's based loosely on how blood moves through the heart. Each side has a single flipper, drain, and ramp. You start with a blue ball representing a deoxygenated red blood cell on the left side with the goal of sending it up a ramp leading to the lungs. This gets you an "oxygenated" red ball on the right side that you're supposed to shoot up a ramp to the rest of the body while the next blue ball launches on the left. The right side also has a "vortex" that fires the red ball out of that side's drain for an easier shot at the ramp.
- Early-Installment Weirdness: This game double downs on the surreal Pop-Up Video Games element of Solar System. In later games, it would be toned down instead. It's also clear that the series formula had not quite been nailed down yet, hence oddities like not being able to exit the bus at every location.
- Exposition Fairy: Like in Solar System, Liz talks and provides you with help when clicked on.
- "Fantastic Voyage" Plot: As in the source material, the basic premise is the bus shrinking and traveling around inside Arnold.
- Gameplay and Story Segregation:
- Even if you're surrounded by liquid, changing the bus into a roofless traction vehicle will have no negative consequences.
- The Arnold Vision screen lets you control Arnold. None of his actions will affect the bus currently inside of him, not even if he sneezes while it's inside his nose, despite that being one of the ways to exit his body.
- Gasshole: In the large intestine experiment, the bacteria will let out a belch upon eating a certain food clicked on to enter the large intestine. This in turn gives Arnold a case of flatulence, to his embarrassment.
- Good Angel, Bad Angel: In Arnold's brain, the magic view shows a devil on one side of the brain and an angel on the other.
- Green Aesop: In the classroom, there's a desk with garbage on it. If you sort out which items go in the trash can and which go in the recycling bin, the desk opens up, giving you access to all the main mini-games at once.
- Harmless Electrocution: While exploring the brain, Carlos can get himself harmlessly electrocuted.
- Hollywood Darkness: Like in the book and TV episode, Arnold's insides are lit well enough for you to see around.
- Hub Level: You can travel anywhere through the nervous system, which can be accessed by turning the bus all the way over to either side of your location.
- Insurmountable Waist-Height Fence: On the Arnold Vision screen, you can make Arnold walk/run to the right or to the left. If he keeps going to the left, he'll eventually be stopped by a wall, and if he keeps going to the right, he'll eventually be stopped by a short fence.
- Magical Security Cam: The Arnold Vision screen shows what Arnold is doing while you're traveling inside him. There are also buttons that allow you to choose his actions.
- Memory Match Mini-Game: In the brain mini-game, Crossed Wires, you're matching items on one side of the screen with items on the other.
- Multiple Endings: After you visit every location, there are three ways you can exit Arnold's body:
- You put a hot chili on his mouth to make him spit out the bus.
- You use a feather to tickle his nose and make him sneeze out the bus.
- You use a water drop on his skin to make him sweat out the bus.
- Oddball in the Series: This game stands apart from the rest of the series for a number of reasons:
- The inside of Arnold's body is rather trippy, what with some of the weird animations you can trigger, the surreal images you can see through the magic view feature, and the constant droning of eerie music. In the other games, the locations you visit are portrayed relatively realistically.
- Much more of the game is spent inside the bus than usual. In fact, there are only a few locations in which you can exit the bus.
- You can transform the bus whenever you want. In every other game, the bus's form is determined entirely by your location, and you can only change it by going to a different location.
- There are twelve locations, thirteen if you count the classroom, which is much more than any other game.
- The student reports are short explanations of scientific phenomena, like the reports in the original books, rather than interactive features like the reports in the other games.
- The game isn't even loosely structured around a Fetch Quest.
- Pop-Up Video Games: In addition to the animations you can trigger in the classroom, most of the organs have clickable items floating by in front of the bus. Some of these items are weird even before you click on them.
- Repeat After Me: When Liz is introduced in the classroom:Ms. Frizzle: Say hello to everybody, Liz.
Liz: Hello to everybody, Liz. - Shades of Suffocation: In the lungs experiment, raising the level of nitrogen will cause Arnold to turn blue.
- Shout-Out:
- In the "Driver's License" segment, Liz says that when you're ready, they'll "hit the road, Jack."
- Keesha notes that, "the gray terrain is mainly in the brain."
- Surreal Humor: The stuff seen in the magic view is pretty strange and fairly unsettling.
- Tooth Fairy: Little tooth fairies fly around in Arnold's mouth.
- To the Tune of…:
- In the classroom, Carlos sings, "my body lies over the ocean."
- In the lungs, Ms. Frizzle sings, "it's a lung way to Tipperary."
- Unlimited Wardrobe: At very location, Ms. Frizzle's dress is different and appropriately themed to the organ that you're visiting.
- Unlockable Content: Every time you travel to a new organ, a new tool is added to Tim's splat kit.
- Video Game Cruelty Potential: Some of the science experiments let you do some pretty weird things to Arnold. The lungs experiment in particular lets the player make Arnold breathe a load of carbon dioxide and nitrogen. On the Arnold Vision screen, you can control Arnold and make him fall down or go into a sneezing fit.
- Warp Whistle: The nervous system allows you to fast travel anywhere. While the other ten organs can all be reached from at least one other organ, the brain and the skin can only be accessed through the nervous system. The brain can also only be exited through the nervous system.
