Greensky Gaming Hits VR Sweet Spot

ID 750960
Updated 12/19/2021
Version Latest



Intel® Software Innovator Justin Link Improves
Grappling and Locomotion in Games

Justin Link of Greensky Games helped develop intense motion VR gaming experiences that don’t bring on cybersickness.

Virtual reality (VR) games can provide amazing experiences but, unfortunately, they can also induce cybersickness – the term for nausea or motion sickness associated with VR gaming. Overcoming this obstacle would significantly increase the number of people who enjoy VR games.

Justin Link, one of the VR Developers at Greensky Games, helped create a physics system that handles the swinging mechanics of SWARM without producing cybersickness. The team at Greensky Games is composed of a handful of developers located around the world, and were engaged by founders Peter Le Bek and Joe Connolly. “Motion sickness is a big barrier to entry for VR for a lot of people,” said Link. “We knew we were making an intense game, so comfort level was always at the forefront of our minds. Making people sick can be a killer.”

Link is also an active contributor to the Intel® Software Innovator Program, Intel’s community for forward-thinking developers. Participants share thought leadership and technology expertise as well as inspire their peers by speaking and giving demos of their work at industry events. Now expanding to support graphics developers and creators, the Intel Software Innovator Program offers an Xe Community track with an emphasis on applications and experiences demanding greater speed and performance even as workloads increase.

Overcoming VR Motion Sickness by Chance

Conquering cybersickness is critical because SWARM differs from many other games in that one cannot stop moving. During the entire game, a player finds themself in a state of perpetual motion while hunting alien robots that invaded Earth. With pistols in each hand a player shoots grappling hooks and blasts lasers at alien robots as they swing from platform to platform. This action requires the player to constantly think about where to fire their next hook. The wrong move means the player stops and becomes an easy target for the robots, or falls and goes splat. Either option means game over.

As fun as this arcade shooter is, it would be a horribly unpleasant experience if Link and the team at Greensky Games failed to identify and eliminate as many factors that can cause cybersickness as possible from their game. For instance, they avoided gameplay situations that force the player to immediately stop moving. “However, only after we asked people without VR gaming experience to test the game did we realize how comfortable SWARM turned out,” said Link.

Swarm offers non-stop first-person shooter action in a comic book world.


Concerning playability and comfort, one game reviewer commented, “SWARM allowed me to pull off some wild moves that I would have thought to be absolutely impossible in VR without painting the room with my lunch,” wrote Eric Hunter.

“Our game style helped us get a bit lucky in regard to motion sickness,” said Link. The core grappling mechanic dictated much of the game design, including the size and scale of the environment and enemies. That makes everything appear to be relatively large and far away. This design was necessary due to the speed the player moves and to provide the ability to easily see and shoot enemies in any position.

The result of the design and gameplay is that, generally, nothing is ever in close proximity to the player. An analogy could be how many people feel nauseous when they read in the car, due to close focus on details within a moving vehicle. The game eliminated that type of behavior.

Another big cause for motion sickness is high levels of parallax. Since nothing ever gets close to the player, the parallax level in SWARM is lower than most games of a
similar intensity. There are no walls that appear to warp or shift, a phenomenon that can make players feel woozy and boxed in.

An additional explanation for why the game is comfortable to play, is that SWARM takes place outside. This keeps a horizon line present in the background virtually throughout the game, helping to anchor the player in space.

The final level, however, does not contain a horizon as it’s played within a volcano. Yet players still report it doesn’t make the game uncomfortable. “Perhaps it’s because by the time a player has reached the final level, they’re more used to VR and cybersickness doesn’t affect them,” said Link.

While it would be incredibly useful if one could state exactly why SWARM does not produce cybersickness, it appears that there’s some serendipity in what makes it an exciting yet comfortable game to play. “There are many variables, we’re not exactly sure which are the primary drivers at play," said Link.

To help demonstrate how SWARM makes VR gameplay nausea free, Link’s colleague at Greensky Games, Stephen Knowles’s grandma is featured in a video entitled, SWARM GRANDMA. The video playfully demonstrates that the game does not trigger cybersickness.

Video: Watch grandma swing and blast alien robots without suffering any motion sickness.

A Voyage in a Different Form of Gameplay

While SWARM is an in-the-moment shooter game, Link’s personal project Voyage relies on strategy and takes an approach to art direction and design that’s atypical of most games.

In Voyage, players must manage their ship, its resources and crew, as they travel on a mission through space. The goal is to reach the final sector with at least one living crew member.

“It mixes elements of some of my favorite games and takes inspiration from classic science fiction movies and shows such as Alien, Star Wars and Star Trek,” says Link.

Voyage is a sci-fi strategy roguelike game that enables players to control a ship and her crew as they search for a gateway to a new sector of space. Along the way the crew must defeat enemy ships. Battles are fought by discovering weak points on an enemy ship and targeting them until the ship is destroyed, all while the enemy attempts to achieve the same result on the player’s ship.

While SWARM is light and full of candy colors, Voyage offers a darker game in both action and tone.


“The player can order its crew to repair weak points while under attack, but they’re vulnerable to enemy fire when they do,” said Link. This provides elements of strategy as the player must consider what actions to take and how they could affect their ship and crew if under attack. “You can keep your crew safe inside the ship during a fight, but when systems get destroyed, they are the only ones who can repair them,” said Link.

Link released a Voyage prototype on Itch so that testers can experience gameplay and provide feedback. The prototype currently offers combat functionality. The next milestones include traveling, a game loop demo, an early access release on Steam, and a full release.

To gain user feedback, Link asks players to respond to a 10-question survey after they play the prototype. “We want to know what's working, what isn't, as well as to comment on design, interaction, experience, and everything that makes Voyage,” said Link.

Link and his team do read all the survey responses, which influences their further development. They also offer players the opportunity to get further involved through their Discord channel.

 Video: To capture the ominous storyline of Voyage, Link created a menacing look and feel.

To represent damage on a ship in Voyage, Link uses a custom-built shader that applies vertex colors. The shader also tessellates and displaces the vertices in damaged areas so that they appear underneath the top base layer. To add elements of motion, debris and particles appear when laser weapons strike the ship. Together they create the overall damage effect on ships.

Video: Voyage prototype showcases the core mechanics of the combat system.

A Process to Design and Development

According to Link, he approaches each project and product differently, but in general he tends to use the following process:

  • Get inspiration and ideate
  • Form a cohesive idea
  • Find references
  • Build a minimum viable product (MVP)
  • Test and evaluate
  • Iterate
  • Polish

“I might repeat steps till I’m ready to move on, and it’s likely I’ll repeat the entire process before something is ready. With games, the more times I do it, the better they become,” said Link.

Reaching the Stars with the Intel® Software Innovator Program

As a member of program since it was officially launched in 2015, and an Intel® Black Belt software developer, Link sees the Intel® Software Innovator Program as a major source of support for the entire community.

“Whether it’s funding and other resources, or marketing on social media and at industry events, the Intel® Software Innovator program has always supported me and my projects,” said Link.

What’s Next on the Event Horizon

On SWARM, Link and his team are working on a highly requested feature: adding a multiplayer option. “We’ve started to roll that out for select players to test,” said Link. The new version will be available on the Quest store and in App Lab. And while work on Voyage appears to be on a break, Link expects to release a new demo sometime in 2022.

Elevate Your Graphics Skills

Ignite inspiration, share achievements, network with peers and get access to experts by becoming an Intel® Software Innovator. Game devs, media developers and other creators can apply to the new Xe Community track – opening a world of opportunity to craft amazing applications, games and experiences running on Xe architecture.

To start connecting and sharing your projects, join the global developer community on Intel® DevMesh.