Jussi Koskela tells us the secret behind the game’s unique feeling of flying.
This is a complicated time for ski jumping in Norway. Interest has been declining for years, with plenty of negative press, and it all peaked recently with the disappointing revelations of widespread suit cheating among Norwegian jumpers. But perhaps we can use this rough patch to reminisce about truly great ski jumping experiences — experiences that, of course, took place in front of a screen.
There have been several games that have given us varying degrees of that wonderful feeling of lift. Growing up, I mostly stared into a screen powered by MS-DOS, and I’m guessing that most of us DOS folks have at some point played The Games: Winter Challenge. It offered a variety of winter sports activities, but let’s be honest — ski jumping was the only fun one. It was incredibly frustrating, though, that it was impossible to land jumps where you actually timed the take-off perfectly.
Back when the New Year’s competition in Garmisch-Partenkirchen felt more important than New Year’s Eve, I was thrilled to discover a little game called Four Hills by Jukka Hakosalo. It let me take part in the whole Four Hills Tournament, competing against legends like Bredesen and Goldberger. The game was very simple, but sometimes it doesn’t take much to be entertained.
But everything changed the year we discovered Deluxe Ski Jump. It was the game we’d been waiting for all along. At last, the ultimate ski jumping game had arrived. We had a chat with the man who gave us this gift more than 25 years ago.
First of all—who are you?
I’m Jussi Koskela, a 45-year-old solo game developer from Finland, and I’ve been working on the Deluxe Ski Jump games since 1999.
How did you get started with game development?
I started making little games already as a child. When I was 9, I wrote my first «game», where the goal was to kill a giant spider by swinging a sword at the right time. You just had to press F1 once to win the game.
Later, my games grew in complexity and size little by little. I sold my first game when I was 12, to a friend who was 7. I think he was mostly interested in the source code…
Can you tell us about your first commercial game, Fatal Fumes?
Fatal Fumes is a top-down racing game I developed as a hobby project in my teens. My brother helped me a bit with the physics, and a friend contributed the music. We also built the tracks together.
For me, Fatal Fumes was mostly a learning project, since it was my first full-scale game. Programming was very different back then because there were no ready-made libraries for sound or graphics, so you had to code everything from scratch. The biggest challenge was getting the game to run smoothly at 70 FPS. I also struggled a bit with implementing CPU opponents who could drive well enough.
Of course, we dreamed of big sales, but Fatal Fumes never became a commercial success. Still, I was very proud that the game’s demo was included on the cover disks of PC Gamer and PC Format magazines in the UK.
My friends and I played Slicks ’n’ Slide a lot, and it was definitely an inspiration for our racing game. Fatal Fumes aimed to be something similar, but with larger tracks that spanned multiple screens. The charm of Slicks ’n’ Slide was always the multiplayer mode on a shared keyboard, but that didn’t work so well in Fatal Fumes, since I never managed to implement proper split-screen.
How did you end up making a new ski jumping simulator?
I had been experimenting with side-scrolling graphics that gave an effective 3D feel. It was originally meant for a platformer, but at some point, it reminded me of a ski jumping hill. I felt that other ski jumping games at the time had very simplistic physics and didn’t really capture the feeling of flight, so I decided to give it a go myself.
What were the biggest challenges you faced?
The biggest challenge was time. I only had three months off after high school before starting military service, and I finished the game just one day before I had to report in!
Technically, the hardest part was making the hills and environments look believable using my «fake» 3D graphics. The actual simulation part was mostly basic high school physics. I never took any programming courses in high school, so experience and code snippets from earlier projects were invaluable.
The most important factor in the game’s success was making the jumping feel fantastic—and I spent a lot of time on that. I think the biggest innovation was how the mouse controls were mapped to the jumper’s movements. It made players respond with their whole bodies, as if they were ski jumpers themselves.
Yes, what is actually the secret behind creating the great jumping feel in DSJ?
I give the player 100% control over the jump, without artificial hints about how to do it. The only feedback is the simulated response on the screen, so the player has to actually feel the ski jump physics. This puts the player directly in the jumper’s boots. Other ski jumping games had indicators for take-off and flight position, which caused players to focus on the UI instead of the jumper – which breaks immersion.
In DSJ, that sense of being the jumper is reinforced by mapping the player’s fingers to the jumper’s legs. During take-off, you press both mouse buttons—just like a real jumper pushes off with both legs. That connection between fingers and legs continues into the landing. This “two-button” mechanic was so unique that some mouse drivers even had trouble registering both buttons at the same time!
My advice to other game developers is to start with the core mechanics. Dare to be unique, fine-tune it until it’s just right – and then build the rest of the game around it.
DSJ is really fun, but it also increased the risk of mouse strain. How much pain do you think you’ve caused your players?
I was aware of the potential risks – not to mention neck stiffness from players tilting their heads to the right – but thankfully I haven’t received many complaints. I suppose virtual ski jumping is still safer than jumping from an actual hill…
It’s been a while since we feared Finnish ski jumpers like Janne Ahonen or Toni Nieminen. How’s ski jumping interest in Finland today?
Interest has declined due to a lack of success on the hill, which in turn makes it harder to find sponsors. It’s a vicious cycle. In my opinion, the decline began when the national broadcaster stopped airing competitions on free TV. Before that, ski jumping was national entertainment.
But interest in DSJ remains high?
All Deluxe Ski Jump games have held up well. In addition to online tournaments, there are still many events for the original DOS version. Last year, I was invited to two such tournaments in Poland, and the players were still very enthusiastic.
In the beginning, most DSJ players came from traditional ski jumping countries like Finland, Norway, Germany, Austria, and Slovenia. But the huge Adam Małysz wave in Poland in the early 2000s changed everything. “Małyszomania” has carried DSJ’s success in Poland right up to today, and currently about 90% of new players are from Poland. Norway’s golden age with DSJ was definitely the early 2000s.
You made a lot of changes in version four of Deluxe Ski Jump. Can you tell us a bit about that process?
My goal has always been to make each release more realistic than the last. The earlier DSJ games had only fictional hills, so the physics didn’t need to match reality very closely.
Up through DSJ 3, I wrote the physics engines myself, but for DSJ 4, I decided to use the Open Dynamics Engine.
For DSJ 4, I had to study human physiology – things like skeleton structure, limb mass, joint movement, and muscle behavior – to ensure the jumper behaved naturally. Some real ski jumpers also gave me valuable data about how the jumper should move during each phase of the jump.
It took months of hard work (and plenty of frustration) to make the simulation both realistic, fun, and highly playable. Hitting two out of three was fairly easy, but achieving all three at once felt nearly impossible. In a simulation like this, everything affects everything else, so even small changes could either fix or ruin the entire experience.
The balance between physical realism and playability is tricky. In DSJ4, everything is geared toward realism, but I had to give the jumper super-strong ankles to ensure that flight adjustments felt responsive. Without that, the controls felt too loose, and players didn’t feel in control.
The game had a sort of «rebirth» in 2020 when I added the ability for players to create their own hills. Since then, the community has produced hundreds of high-quality hills—most of them far more detailed than any I’ve made myself.
What are you working on these days?
In addition to working part-time at a non-game software company, I also work part-time on Deluxe Ski Jump and a new update for version 4.
The next update will focus on improving the offline game mode and making it more configurable. It’ll be possible to compete in new formats (e.g., super teams) and run multiple parallel tournaments and cups. Almost everything will be adjustable—even after the season has started.
Finally, we’re impressed by the Finnish Museum of Games, is your game represented in the museum?
Yes, Deluxe Ski Jump is featured at the Finnish Museum of Games. Visitors can play DSJ2, and they also have some of my original sketches, the DSJ mouse, and a ski jumper toy from my childhood on display.
We thank Jussi Koskela for the chat and look forward to seeing what the future holds for Deluxe Ski Jump. Visit the official site to find out more about the game.
The images are supplied by Jussi himself, or taken from Mobygames.
Article by Jon Håvard Gundersen.
We have more content in English, including interviews and features. You can find it here. This article is also available in Norwegian.