New York (CNN) -- Dennis Crowley was jogging across a New York bridge when he spotted something exciting: a cartoon mushroom, spray-painted on the sidewalk.
It looked like something out of Nintendo's "Super Mario Bros.," which Crowley grew up playing. He stomped on the mushroom as he ran by and had a sort of nerdy realization.
"I was like, s---!" he recalled. " 'I should get a power-up for that!' "
Since that moment several years ago, Crowley -- a 33-year-old who's always in a sweatshirt and wears an eyebrow-length mop of Justin Bieber-like hair -- has sought to turn adult life into a whimsical game. In his world, people should earn points and prizes for making random discoveries like that one.
His latest venture, a popular smartphone app called Foursquare, lets players use their phones to "check in" to the various restaurants, bars, art galleries and friends' apartments they visit in the course of their day. With each stop, they earn points; people who complete special challenges -- like visiting 20 pizza joints, staying out past 3 a.m. on a "school night" or being a serial karaoke singer -- get special merit badges, as if they were digital Boy Scouts.
Crowley sees these video-game-style rewards as reason enough for Foursquare users to make more effort to explore the real world -- and, in the process, to have more fun with their daily lives.
That puts the app, which launched in 2009, right in line with what seems to be his personal philosophy: "Things shouldn't be so super-serious all the time."
But does the game-centered life Foursquare promotes lead to success and fulfillment?
CNN followed Crowley for 24 hours in New York to find out.
The answer seems to be located in the places he frequents, whether he "checks in" there or not.
@Play (the Scratcher): 209 E. Fifth St., New York
By his own count, Crowley has about 60 close friends in Manhattan's East Village, the gritty and artsy corner of New York where he lives, works and plays.
He sees some subset of this group every day, since when he leaves the office about 8 p.m., he almost always goes somewhere besides home.
You'd think an out-every-night social calendar would require some intense forethought, but not for Crowley. He just looks at his phone. Opens the Foursquare app. And it tells him exactly where his close friends are.
Then he heads out to meet them, sometimes after sending a courtesy text message.
"I still call people, but if I'm at home on my couch on a Tuesday, I'll check Foursquare to see if anyone's out and nearby," he said, "and I'll send them a text and be like, 'Yo! Can I meet up with you in a bit?' "
Lately, Crowley frequently finds these friends at his favorite bar, the Scratcher, a basement-level hole-in-the wall on Fifth Street. Crowley has been there 49 times since 2002, when he started counting. That has earned him the Foursquare honor of being "mayor" of that venue, meaning he has checked in there more times than anyone else.
Even when he's sick, Crowley feels hard-pressed to turn down a night at the Scratcher -- partly because it's fun but also because he has to keep going to the bar as often as possible to avoid getting beat out of his mayorship by another frequent patron. And it's the only mayorship he holds these days.
Case in point: On a recent Tuesday night, when Crowley had a nagging cough and said he'd been sick for three weeks, he went out first to the Scratcher and then ended up staying out on the town, singing karaoke ("Patience" by Guns N' Roses is his go-to song), until about 2 a.m.
He still made it to work the next morning, though.
"I've def been *less* hungover :)," he posted on his Twitter feed at 7:08 a.m.
Crowley said he's the kind of person who will stretch his social schedule to explore the city but would go to the same places all the time unless he had a little "kick in the ass" to try someplace else.
Again, that's where Foursquare comes in.
With badges and coupons, Foursquare has rewarded Crowley for doing simple things like going to Brooklyn frequently, traveling above New York's 59th Street, going to work with a hangover (since the app knows how late he's been out), visiting more than 10 playgrounds and going to Omaha, Nebraska. In all, he's earned 51 digital badges through the app he created; he's "checked in" with Foursquare nearly 3,500 times.
All this moving about gives some observers the sense that Crowley is everywhere and nowhere all at the same time. At dinner and at drinks, he's often on his phone, updating his location and text-messaging constantly.
Alex Rainert, Foursquare's product manager and a longtime friend, said these social interactions sustain Crowley.
"I think that's what rejuvenates him," Rainert said of Crowley's social calendar.
"It's very much the same spirit that drives the product," he said. "You could go home and decompress, or you could go to that art gallery someone's recommended."
Crowley will always choose the gallery.
And, since he's done so 10 times or more, he's earned the "Warhol" badge.
@Youth: Medway, Massachusetts
Crowley's obsession with games and rewards started early.
Growing up in Medway, Massachusetts, a town of about 12,500 people, Crowley wasn't all that good at sports or academics, according to family members, but he was extremely competitive when it came to video games and practical jokes.
The oldest of three kids, Crowley used any chance he could get to assert his superiority over his younger brother and sister. Jonathan Crowley recalls a time when his older brother smashed two forts he had built in the backyard. When Jonathan built a third, he put the fort in a tree so Dennis couldn't get to it.
But he came home to find that Dennis had cut the trees down in order to make the fort fall, he said.
"We're super-competitive in everything we do," said Jonathan Crowley, 30, who laughs when he talks about his childhood fights with his older brother. "Our dad raised us to be competitive -- for better or for worse."
Their father also raised his kids to be independent. Dennis Crowley, who goes by the same name as his oldest son, started his own communications business, which later became part of General Electric. He told his kids that if they really wanted to succeed, they had to work for themselves, not for someone else.
By early high school, the younger Dennis had taken this advice to heart.
When he wasn't playing video games, skateboarding or following around graffiti artists, he was writing, editing and printing a video-game-centered magazine called Dystopia, which he sold in local video game arcades and stores.
"We played video games as well, but he would take it to another level," Jonathan Crowley said. "He'd be like, writing down the codes, writing down the moves and figuring out a way to share that with people."
Dennis Crowley carried that same vigor and industriousness into many activities, whether they were serious or not.
In 2008, when the Crowleys were picked to be on the television game show "Family Feud," Dennis and Jonathan devised a rigorous -- but fun -- practice schedule for the entire family. In the family ski house in Vermont, they set a microwave timer for 20 seconds and practiced answering questions for the show's final round, which is called "fast money."
They quizzed each other in person and over e-mail for four or five months before the show was taped, Jonathan Crowley said.
During the actual competition, Jonathan Crowley recalls a moment when he and his brother froze, unable to comprehend the hugeness of the fact that this was a real game in real life, with real money at stake.
But then they locked eyes on the set, and everything was OK.
"We're both like, 'holy s---! This is no microwave-timer anymore. This is the real deal ... and we can do it!' " he said.
The family walked away as winners, with a $20,000 prize.
@School (New York University): 721 Broadway, New York
After graduating with a communications and advertising degree from Syracuse University and working for a time at tech investment and research firms, Dennis Crowley had one big reason for wanting to go to graduate school: to play.
For that, he picked the perfect place: the Interactive Telecommunications Program at New York University, which he described as "Alice in Wonderland" for adults, "a playground where you get these crazy tinkerers messing around; it's a fantasy land in some ways; it's art school."
Walk through the school today, and you'll still see evidence of Crowley's playful and game-themed grad-school projects:
In a large workspace, for example, there's a foosball table where some of the plastic players are wearing knit shirts and numbers. It's hooked up to a microprocessor and sensors that automatically record goals and, in Crowley's day, posted wins and losses on a tournament-style leader board on the wall.
"I had, like, problems with my wrist from playing a lot," he remembered fondly.
Obsessed with the idea that life should be more like a game, Crowley also took these ideas out of the classroom. With a group of other NYU students, he helped organize a real-world game called PacManhattan, a combination of the arcade game "Pac-Man" and the New York borough.
The students dressed up like the games characters -- Crowley was Pac-Man during the first test -- and ran through the streets of New York, as if the city were their arcade board.
Because GPS technology was clunky at the time, they called in their locations to a central processing station by mobile phone. An operator manually input their whereabouts in a computer program and tallied the winners and losers.
"I just like building tools that make the city more interesting," he said.
The next logical step was to make everyday interactions more game-like.
As his NYU thesis project, in collaboration with Rainert, Crowley upgraded a long-time project of his called Dodgeball, a text-message-based social network that, in many ways, is the precursor to Foursquare.
People used Dodgeball to tell a central computer at NYU where they were. Friends got text updates on their whereabouts, and all of a sudden, this system was holding together Crowley's large social network in the East Village.
The system got so big that, in 2005, Google bought Dodgeball from Crowley for an undisclosed sum of money (enough to buy an "old-school" Range Rover, like the one from older Beastie Boys music videos, which Crowley loves).
That might seem like a success story.
But, for Crowley, it wasn't. Soon, everything fell apart.
@Work (Foursquare): 36 Cooper Square, New York
Foursquare shares its 2,000-square-foot office space -- on the fifth floor of the Village Voice newspaper building -- with two other start-up companies.
Workers sit side by side at long tables that look like they belong in at an elementary school cafeteria. Crowley says the place is starting to get the feel of a "sweatshop" as Foursquare adds workers, seemingly each week.
But if Foursquare is a sweatshop, it seems to be a happy one. Even though everyone seems to work long hours in crowded, hot conditions, Crowley does his best to make work life into a game, just like in the app.
The office bookshelf does contain some books: "Jamie's Food Revolution," "Broke-Ass Stuart's Guide To Living Cheaply in New York" and "I Won't Give Up," which chronicles the life of rocker Pete Doherty. But those are side-by-side with bottles of vodka and Cabernet Sauvignon, plastic cups and board games like Clue. Michael Jackson playing cards and meeting notes with titles like "Product Dreams," "Next" and "Fantasy Use Cases" are tacked to the walls.
On a Wednesday afternoon in late May, Crowley had his Nike sneakers up in a chair as he talked with Rainert, Foursquare's product developer, about the future of the company. They started off discussing to-do lists in the app, which let players keep track of tips and suggestions they find in Foursquare.
Crowley is notoriously critical of his own work.
"People love it, but [the to-do lists] suck," Crowley said. "Things that you want to do should be, like, super-pure."
Of one potential fix, he said: "God, that's so f---ing hot." The next was "half-baked." Another was "too wonky" to go in the app, he decided.
When Crowley leaves the office on business, he takes this uninhibited aura with him. At the South by Southwest Interactive conference in Austin, Texas, for example, Crowley "swam" an annual backstroke race across a hotel lobby -- flailing about on his back on the marble -- in the wee hours of the morning.
Even when he's making a pitch for his company, a bit of playfulness is always at the ready. At a May technology conference in New York, a blogger asked Crowley whether he planned to sell the company, as is widely rumored.
"Oh, I already sold. We sold to Nabisco [the cookie maker]," he responded. "We think it's going to be a good fit."
Crowley's dad and brother have worried that his uber-casual and playful persona won't go over well in the business world.
And as Foursquare continues to get more popular -- it now has nearly 1.5 million users -- it's clear that Crowley is feeling pressured. His e-mail inbox is overflowing. His iPhone blinks, at times, like it's a strobe light.
He also has the fact that Dodgeball failed staring him over the shoulder.
"None of my stuff works. It's all been broken. I've never not had a failure," Crowley said. "We just haven't made this fail yet."
@Unemployment (Tompkins Square Park): 500 E. Ninth St., New York
When Google bought Dodgeball, it seemed like everything was going right. He'd sold his company to the world's search-engine giant. And he had landed a job at the company, too.
But in 2007, Crowley left Google in a huff, publicly complaining that it hadn't given him the resources he needed to make Dodgeball succeed.
With his intellectual baby out of his hands, he went into a deep funk. He wasn't sure what to do, so he traveled the world a bit and spent much of his time reading magazines in Tompkins Square Park, near his apartment in New York.
Then one of his worst fears became reality.
In January 2009, Google shut down Dodgeball's servers for good.
His social network had dissolved.
But he didn't mope forever. The Dodgeball shutdown ended up being just the kick-start Crowley needed.
He met up with another unemployed tech geek, Naveen Selvadurai, the same month Dodgeball became extinct. They drew up the blueprints for Foursquare in Crowley's kitchen and in coffee shops and then founded the company.
Crowley says he started Foursquare for his circle of East Village friends. He never intended for it to become this successful.
He just needed a new social glue.
He has that back now. And as it turns out, failure may have been one of the better things to happen to Crowley.
On his Twitter account, Crowley lists "unemployment" as one of his interests:
"I like snowboards, foursquare and unemployment," his online bio says.
@Home: Near Tompkins Square Park, East Village, New York
There are no winners and losers in the game of Foursquare.
And that's intentional.
As Rainert, Foursquare's product manager, put it: "It's not about winning; it's about doing more stuff."
Crowley put it more bluntly.
"You don't want to tell people they're winning at life or they're not," he said.
He says he doesn't define Foursquare's success by the number of people who use his app or by the amount of money it makes. He wants some people to use it -- and for it to be a life-enriching experience for those who do.
Maybe the app will inject a bit of Crowley's carefree spirit into the daily grind.
If anything, Crowley seems most adamant about seeing this project through to the end -- and on getting as many of the ideas that are boiling in his head out into the real world. That's something he can't say about Dodgeball.
As his dad said, "He tells me that what they're doing [with Foursquare] is just the tip of the iceberg."
At his spare, IKEA-decorated apartment in New York's East Village, Crowley has a shelf that's home to board games and a vase full of Legos.
On top, next to a picture of a car, there's also a soccer trophy.
The trophy shows a side of Crowley that he doesn't let most people to see.
"Don't read too much into that," he said. "That's the trophy they give to every kid that plays. It's like, you show up and you get it."
In a way, playing is as important to him as winning.