3583 Bytes

Adam Berent, Founder

Calgary, Canada

Train Sim: players can drive locomotives like the Siemens Charger in this free-to-play train simulator.

2026

All aboard: how 3583 Bytes built a train sim that keeps on rolling

3583 Bytes got its start as Adam Berent’s Unity project for building Train Sim for his train-obsessed 18-month-old son at the time. Today, his son is all grown up, but so has Train Sim — to the tune of 34 million downloads to be precise. But Adam still keeps chugging along, working on keeping the experience free for players by monetizing with ads, while regularly shipping updates and staying close to his community by email and on Discord.

First spark at the station

All Adam Berent, founder of indie studio 3583 Bytes, ever wanted was a simple train game for his train-obsessed 1½-year-old son. But alas, nothing in the Google Play Store quite fit what he had in mind.

So, as all entrepreneurs tend to do, he set out to solve the problem himself.

He made the first version of his train game in Unity on a laptop. His son loved it. Adam put it up on Google Play. And soon enough, the rest of the world’s train-obsessed loved it too.

“Within the first month, Train Sim had been downloaded over a million times on Android, pushing it into Google Play’s top 100 Casual Games,” Adam remembers fondly.

Adam also credits that first game’s success to timing: “I picked a good name and I was early enough such that when you type ‘train sim’ or ‘train simulator,’ I showed up at the very top of the search results.”

And that’s how 3583 Bytes got its start. Even the company name gives a nod to scrappiness: 3583 bytes. That was the amount of free program memory you’d have if you had gotten your hands on the vintage VIC-20 microcomputer. “Enough [memory] to hold about a single page of text,” as Adam puts it.

And yet… people still built games on it. So Adam took the name for his own, a reminder that you can still do a lot with limited resources.

Train Sim: players can drive bullet trains like the Shinkansen S300.

A free ride, powered by ads

Ask Adam why he monetizes the way he does, and he'll respond as a matter of factly, “I wanted my game to be free.”

That’s the spirit behind the ad-supported business model, which makes a lot of sense for free-to-download apps: you can offer an experience to everyone, regardless of who can pay, while still funding the work it takes.

Adam understood that as well, and put ads into Train Sim early. But he quickly learned an ugly lesson: not all ad solutions are created equal.

He started with a provider that was “super easy to integrate” in Unity. “You just import a package and you’re done.” Except, a few months later, the company went belly up, and Adam lost all that revenue.

Then there’s that other very important issue: player trust.

When ads are designed to try and trick players, for instance, by making the close button hard to see, or placing it in a way that causes people to accidentally click, people end up pointing their fingers at the developer.

“My players couldn’t close the ads,” Adam says, referring to some monetization platforms that he’s tried in the past. “My ratings went down as a result.”

Enter Google AdMob.

“That’s when I switched to AdMob and I haven’t looked back since,” he says. “I’m going to stick with somebody that’s going to be in business 10 years from now, and who cares about the player experience too.”

That’s why, to this very day, most of the business still runs on AdMob’s ads. Adam estimates about 90% of his revenue comes from them, with the balance coming from a smaller group of players who make an in-app purchase to turn off ads.

“That’s when I switched to AdMob and I haven’t looked back since. I’m going to stick with somebody that’s going to be in business 10 years from now, and who cares about the player experience too.”

Train Sim keeps attracting new fans and bringing back existing ones to explore its 70+ train models.

The next stop

These days, Adam’s got plenty of reasons to celebrate — 34 million of them, to be exact. That’s how many downloads Train Sim recently cleared.

That’s proof that the game still hits the mark with the train-obsessed.

In fact, the game’s been around long enough that some of the early players are now coming back, downloading it again as adults, for the nostalgia effect.

As for Adam, he’s managed to parlay his success with Train Sim into a portfolio of other sims over the years. There’s Dinosaur Sim, Flight Sim, even Aquarium Sim. But Train Sim is still the one that gets most of his TLC: “seven, eight updates a year.”

Not only that, but running 3583 Bytes (alongside his full-time job) has been rewarding in and of itself. Pick any evening, and you’re bound to find Adam sitting on the couch with his laptop, watching TV with his wife, coding, tinkering, making the next update happen. “It doesn’t even feel like work; it’s kind of relaxing actually,” he reflects.

It also helps that he’s constantly reminded that there are real people on the other side of that laptop screen of his.

Adam gets regular emails from customers, even sharing some of his favorites on the Train Sim page. But the conversations don’t end with his inbox. Adam also runs a Discord on the side, where he chats directly with fans, shares beta builds, and collects feedback.

As for what the future holds for his one-man studio, Adam is clear eyed: launching new apps is harder these days — that train has definitely left the station. So he has to plan his next steps carefully, moving slower, but smarter too.

Adam says he'll probably add more games, but would cross-promote anything new from his existing apps, something that he can introduce to all those existing Train Sim players he’s already got.

Those players can rest assured, though. Most of his energy is still going to be spent on the flagship: listening to feedback, pushing updates, emailing one minute, Discord-ing the next, all to keep Train Sim competitive, “so that there isn’t somebody that comes in, knocks me out, and makes a better game.”

Sure, Train Sim may have millions of downloads now, but when Adam pauses to think about it, he realizes he’s still building for a party of one: his son…or at least, the 18-month-old version of him who was just over the moon about trains.

He hopes the next kid with a train phase will love it the way his son did.

About the Publisher

Adam Berent is the founder of indie studio 3583 Bytes based out of Calgary, Canada. A software development manager by day, Adam dons his game developer hat by night, originally creating Train Sim for his toddler son and his train phase, later publishing it to Google Play, where it's grown into a long-running title, now 34 million downloads strong, and counting. He continues to build and update Train Sim, keeping laser focused on a good, trustworthy player experience that’s offered free with advertising.

Adam Berent, founder of 3583 Bytes based out of Calgary, Canada, and creator of the Train Sim mobile game.