Skyball

1/4

A one-time VR arcade game and exhibit, developed for the Galeries Saint-George mall in Toulouse, France.

As it was intended to be played in the middle of the mall by passers-by, the design of Skyball had several constraints. A single game had to be short (between five and ten minutes) it had to be playable by gamers and non-gamers alike (especially people not used to VR games), and it should preferably be a game that was as entertaining to watch as it was to play.

These constraints shaped Skyball into an "arcade-VR" game, in which the player had to use two gun-like tools to collect score cubes scattered around the arena while pushing away spiky bombs constantly rolling toward them.

Design highlights

Gameplay

Since we wanted the game to be simple and accessible, we decided that the player would only ever need to press the triggers of the controllers to play. It naturally led us to make the tools of the player in the shape of guns, which made them evocative and made it easy to understand how to use them.

In the earliest versions, the guns were floating in the center of the arena, waiting for the player to pick them up. As soon as this was done, the first wave was spawned and the game countdown started. The intention behind this was to allow the players a time to familiarize themselves with the controls, especially since a lot of people are unfamiliar with the locomotion systems of VR games. However, we realized very early on that it was actually very difficult for players to pick up the guns, making them unable to start the game! This was due to the aforementioned unfamiliarity with VR locomotion (people had a hard time teleporting in the right place to pick up the guns) and because picking up a gun required pressing the thumb button of the controller, which was very hard to feel and to press because of its size, even for people used to video games.

We corrected this by making the player spawn with guns in hand from the start, and we kept the familiarization time by simply asking them to step into a cylinder of green light at the center of the arena to spawn the first wave.

The two guns are different visually and in their purpose. The right-hand one is red and has a barrel looking a bit like a plane engine. When the trigger is pressed, it blows a stream of air forward that can push the bombs away. This stream applies a physical force to whatever it touches, so it is affected by the weight of its target and the time spend pushing it, requiring the player to keep aiming correctly to push heavier enemies effectively.

The left-hand one is blue and its barrel looks like a U-magnet. When used, it creates electric sparks going towards it and attracts anything it their path to the player. It is used to collect the score cubes that are scattered on the arena at the start of each new wave. However, it can also attract bombs, so the player has to be careful when aiming with it.

The goal of the game was to get the highest score by collecting score cubes. The game ended either when the player was hit three times by a bomb, or when the fifteen-minutes countdown reached zero. At the end of the game, the player had the option to enter their name into the leaderboard if they scored high enough. Despite this, Skyball failed to create meaningful play in the first versions, as people felt there was no point in getting a high score. To adress this, we implemented a 'level up' mechanic: after a set number of cubes collected without being harmed, a sound and visual effect was played to tell the player they gained a level. Each level increased the power of both guns, and it also increased the size of the particles they produced to enhance the game feel.

We also added a dynamic music system, with a new instrumental layer added after every wave passed, and resetting to default when the player lost a life. This was a great addition to the game's experience and became a favorite feature of most players.

Enemies

As a physics-based game, it was an obvious choice for me to give a spheric shape to the enemies. This shape was ideal for several reasons :

It allowed me to create a simple yet effective force-based movement behavior;
It used a primitive collider and thus was very performance-friendly;
It made iterating on the 3d model fast and unexpensive.

Once spawned, the bombs move toward the player pushed by a constant invisible force pointing towards the player's position. Since their movement is entirely force-based, it allows the player to take advantage of their momentum to outmaneuver them, for instance by standing near the edge of the arena and suddenly moving just before impact, making the bomb fall out of the bounds like a charging bull.

There is only one type of enemy, but it has a large gradient of variation. At the beginning of the game, only medium-sized bombs are spawned, but with each subsequent wave the degree of variation expands in both directions (larger and smaller bombs are spawned). All bombs glow in a color ranging from yellow for the biggest to red for the smallest, produce an alarm sound whose pitch depends on their size, and of course weigh differently depending on their size as well. This allows for a wide range of variation between enemies, with extremes that require different skills to be defeated.

Because of their massive weight, the largest bombs are slow and easy to dodge, but are difficult to push away. On the opposite side, the smallest bombs are fast, hard to aim at and make a very stressful high-pitched noise, but their lightness makes them fly away into the sky as soon as the player manages to shoot them.

Post-mortem

Overall, Skyball succeeded in creating a fun, short and engaging experience. Playtime for one game was generally between two and ten minutes, which was perfect since it allowed many players to try out the game without waiting too long. The majority of players found the game fun, however some issues still remained even in the final stages.

Despite our focus on accessibility, some people still were unable to understand or even play the game. This was especially true for older people or people who never played video games.
The game received some criticism for its visuals, that people found unappealing.

To adress this issues, we should have done several things:

More concept art should have been produced for several game elements before switching to production, and the artistic direction could have been defined more clearly.
We should either have conducted more research and studies about accessibilty for non-gamers, or redefined our target audience to design en experience better aimed at our chosen demographic.