The orangutans are unhappy. You can tell because of the tiny, red frowning faces that have popped up above their heads. Sometimes, it’s because the wrong food has been placed in their habitat. They hate the trees that you’ve planted. Maybe you can’t keep up with the animal poop, and now the zoo’s patrons are throwing up, too. This is a normal day at work in Blue Fang’s Zoo Tycoon, the management simulation game published by Microsoft in 2001.

As a kid, I wanted nothing more than to be in the presence of all the animals I loved, whether that was scooping their poop or studying their movement. Plenty of my friends did, too. We lived out these fantasies in books and by playing pretend, dreaming up the research centers we’d fund, the animals we’d rehabilitate, and the fur we’d snuggle up to at night. For many of us, we realized the unlikeliness of these dreams becoming reality. Many wild animals won’t thrive in captivity — there are many for-profit zoos that are, frankly, inhumane — and being a zookeeper certainly didn’t mean we’d be petting wild animals day-by-day.

I was 13 when Zoo Tycoon was released. I wanted to be a veterinarian — someone who helped injured animals, the wilder the better. I was enamored by Zoo Tycoon and the freedom it gave me to create something in a way I’d only ever dream about. In particular, I remember building a single enclosure the size of the lot for a pride of lions, my favorite animal at the time. I spent hours constructing the perfect environment from them: all the right trees for shade, lots of dirt, and plenty of food. I tested out scenarios, adding gazelles and other animals to the enclosures. They never lasted long.

Zoo Tycoon was popular for plenty of reasons, among them the ability to curate your own experience. Players could pick and choose how to play. There is, of course, a technical way to win: engage in the capitalistic practice of increasing profits. You are a tycoon, after all. But the reason many latched onto the game is because they could play it however they pleased. I used cheats to have infinite money, and I never had to worry about guest satisfaction. Instead, I just watched the animals interact. In more mischievous moments, I created zoos for the sole purpose of reigning chaos, “forgetting” to close in an animal only for it to wreak havoc on my guests.

Just like in The Sims, I was telling my stories — just with animals instead of humans.

Building the zoo

Blue Fang started with a small team of developers set up in co-founder Adam Levesque’s basement.

“We were just starting out and didn’t really have money to spend on an expensive office space,” Levesque told Polygon. “My wife said it was alright, and we just packed into the space — well, not really packed. There were four of us.”

But the company moved into an office when it began work on Zoo Tycoon, growing from those first four to 20 employees. But before there was Zoo Tycoon, Blue Fang considered another simulation-style game: Airport Tycoon. Like Zoo Tycoon, it was meant to be a riff on game developer Chris Sawyer’s 1999 theme park sim RollerCoaster Tycoon. The idea didn’t make it far out of Blue Fang president Hank Howie’s office after being suggested by studio co-founder John Wheeler.

“I get the ‘Tycoon’ thing,” Howie told Wheeler, the former studio president told Polygon. “But RollerCoaster Tycoon is popular because there’s roller coasters. They’re fun places. Airports aren’t fun places for the most part. People are usually stressed out.”

But RollerCoaster Tycoon is popular because there’s roller coasters. They’re fun places. Airports aren’t fun places for the most part. People are usually stressed out.

Howie said that Wheeler asked him not to mention the idea to anyone while he worked it out.

“Of course, the next person who walked into my office, I mentioned it to them,” Howie said. “That was Brian Shea, one of our very early employees. And he says, ‘Airport Tycoon? Why wouldn’t we make, like, Zoo Tycoon?’”

Zoo Tycoon was not wildly different than the other tycoon games popular in the late ’90s. RollerCoaster Tycoon can be credited for the increase of tycoon-esque games that were released in the 2000s, but it certainly wasn’t the first. Before it, there were plenty of games that took on the “Tycoon” naming convention and shared similar gameplay: MicroProse’s Sid Meier’s Railroad Tycoon, Software 2000’s Pizza Tycoon, and another game by RollerCoaster Tycoon creator Sawyer, Transport Tycoon.

Zoo Tycoon starts with a plot of land. Players must clear land to gain resources to build enclosures, each of which will differ depending on the animal that’ll live there. Wheeler said it was important that there were few barriers to entry. All you need to do to start is to build a fence. From there, animals can live together or alone, depending on preference. Some animals can live in habitats that mimic their natural environment — each has needs that need to be met to keep the animals happy, including habitat, diet, shelter, and enrichment.

“[The team] quickly became experts on animal behavior and zoology,” Howie said. “They almost attained an Encyclopedia-level knowledge of animal behaviors and environments.”

Education, but make it fun

Blue Fang art director Fred Galpern said that there was tons of research involved in the development of Zoo Tycoon.

“We went to all the zoos in and around the Boston area,” Galpern said. “We even sent a team out to the San Francisco Zoo to do a visit. And this is just the art folks, concept artists, and animators. It was really important to us to understand the reality around these animals, what they were like, and what their environments were like.”

Levesque said he read plenty of books ahead of development, ranging from zoo design to the ethics of keeping animals in captivity. He talked with zookeepers, observed animals, and thought deeply about how it all could translate into gameplay. Blue Fang considered everything, including poop. Wheeler showed me a reference book, “The Encyclopedia of Poo,” from development when I visited him at his Massachusetts home to talk about the game.

All of that heavy research was so that the development and art teams could break some of the rules when needed. You need to understand the rules in order to adjust things in a way that still makes sense. After all, Zoo Tycoon is a game, and Blue Fang took some liberties with its design. (A future expansion pack added dinosaurs, and as far as we know, you can’t find those in your local zoo.)

“In Marine Mania, [a Zoo Tycoon expansion], we studied real dolphins, but we wanted our dolphins to have their own character,” Galpern said. “There were certain flips that real dolphins couldn’t do, but it was more fun to have our dolphins do things that weren’t perfectly realistic.”

The team wanted the core game to remain grounded enough for it to have an educational aspect, something that players could learn from, while still feeling very distinctly like a game, unlike some of the more education-forward games of the time.

If you want the grizzly bear to escape, you’ve got to name it Deer.

“The whole goal was to have an experience where there’s a bit of balance,” Galpern said. “We wanted parents to endorse their kids playing this game because it had that connection to reality. But once we got through the parents, we wanted the kids to just really have fun.”

Among those educational aspects, there were small details of Zoo Tycoon hidden in the game’s code, elements that were just for fun or intended to be enjoyed by an older audience.

There are less hidden things, like Santa Claus appearing in-game on Christmas. On Halloween, Zoo Tycoon gets spooky with a witch flying over the map. (Wheeler said they got some complaints about that one, from folks who weren’t happy to see witches in the game.) Others are a bit harder to find, tied to the names players can give guests that enter their zoos. Name a guest “Alfred H” and a swarm of birds will fly over your zoo and terrify your guests, a reference to Alfred Hitchcock’s movie adaptation of “The Birds.” Name a different guest “George W” and all the zoo’s trees disappear. Perhaps a jab at George W. Bush’s environmental policies or the tale of George Washington chopping down a cherry tree?

If you want the grizzly bear to escape, you’ve got to name it Deer. To unlock yellow bricks for a pathway, you’d build an exhibit that houses a lion, tiger, and bear. And penguins? In Zoo Tycoon, they’re vicious killers, able to annihilate plenty of other animals in the game — despite their proclivity for dancing in their enclosures.

A commercial success

All of the different things to explore, from the Easter eggs to animal facts and the limits of the game’s sandbox design, played into Zoo Tycoon’s massive success. With a budget of $2 million from publisher Microsoft, Blue Fang didn’t expect to make much money in royalties. Money would first go to paying back that advance. Once that was paid back, Blue Fang would earn royalties, but Howie said that they thought making much after that would be difficult. The team was pleasantly surprised when its first check for “$150,000 or $200,000” was sent through. So then a check for the second quarter showed up — $1.75 million — the team at Blue Fang fully realized the game’s reach, Howie said. (Zoo Tycoon would go on to make a lot more money.)

“The way small studios work is that you basically say, ‘This is how much it’s going to take for us to create this game,’ then you work with a publisher on that,” Levesque added. “You have to pay that advance back before you see any profits. When we realized we had paid that advance back because sales of the game had been doing so well, we were shocked. It was very hard to be an independent studio and be successful. It was really exciting.”

Zoo Tycoon may not have had a lot of influence over the genre technically, but its freedom and expansiveness combined with an undercurrent of education made it appealing to many.

“The game wasn’t revolutionary or breaking ground technically, or even subject matter-wise,” Levesque said. “For us, though, it was a game that everybody could play. It could be educational without being an education game.”