Combining pinball with platforming to build the levels of Yoku's Island Express

The perennially popular game of pinball has appeared in video games in all sorts of forms, from Pinball for the NES in 1983 and the classic Sonic the Hedgehog Spinball in 1993 to Zen Studios' modern Pinball FX series.

Thing is, both these and the many iterations that followed were somewhat straightforward adaptations of the classic pinball board to a digital format.

By contrast, Yoku’s Island Express, developed by Villa Gorilla using their own engine and released last month, mixes the game of pinball up within a colorful platformer and finishes it with a splash of Metroidvania. 

Players take control of Yoku, a dung beetle attached to a ball by a string, and explore a massive map of interconnected “tables”, solving puzzles and meeting the townsfolk by delivering their mail as the new postmaster.

In the beginning, the game was envisioned as a project that would primarily rely on its art style. “Because of the team constellation when starting off, we wanted to make a game that could focus on beautiful art without relying too heavily on animation. So, we began with a ball, and pinball followed that quite naturally,” says level designer and writer Linus Larsson.

But the team knew they had to stand out from other digital pinball games in some way. During prototyping, it didn’t take long to realize that beautiful tables weren’t enough to make an interesting game. Now, the ball needed to be introduced as a character, and Villa Gorilla wanted a lot more room than what traditional pinball tables would afford them.

“This led to tables that were attached to connecting areas and the inclusion of Yoku the dung beetle to push the ball around them”, adds Larsson. “[That] was the state of the project for a while, but we soon realized that those in-between areas were where the game really felt unique. Because of this we made a major direction change: stepping away from pinball levels and transition areas and going for an open world Metroidvania design instead.”

As the initial design closely resembled traditional pinball, there were a lot of "pure" mechanics that needed to be adjusted: a score system, combos and extra balls that represented lives were scrapped and replaced by bigger exploration areas, more NPCs and secrets to uncover all around Mokumana Island.

A dev-provided clip of the journey from concept to functional pinball-platforming level

“With our shift in focus towards a more adventure- [and] exploration-driven game we also started to see that our game was at its best when it was relaxed and chill," explains Larsson. "This was in direct conflict with the stress of pinball, so many of the traditional elements had to be dropped.”

“Somewhere in all this we stopped thinking of our fruits as score and instead as a currency that could interact with our gameworld,” he adds. In Yoku’s Island Express, fruit is now found laying on the ground, hidden in chests or boxes, and as rewards for many of the player’s actions, from hitting certain bumpers to making progress in either a ‘table’ or throughout the story.

“The initial design for this was a 'skill tree-esque' system that contained a large portion of the game rewards called ‘The Fruit Altar’." Larsson continues. "The feature was a lot of fun, but it cannibalized elements from the exploration part of the game.”

A prototype version of the Fruit Altar

The problem was that most of the rewards would be available to unlock in the Altar, leaving very little to be found on the island itself. The team also struggled in narrowing the design down in a way where the Fruit Altar would fit into the world, scrambling to come up with a meaningful reason for its location and purpose in the story.

Ultimately, Larsson says the team concluded that it needed to be cut in favor of scattering more rewards throughout the levels. “In the end we went with the system you see in game today: where fruits are spent to unlock flippers and rewards are scattered around the island in chests for you to find.”

Of course, mixing those levels and exploration-based rewards up with the elements of pinball was no easy task. To manage it, Villa Gorilla initially considered doing two separate game modes: in Flipper Mode you would control the ball and the flippers, and in Adventure you would play solely as Yoku.

An early prototype of the "Adventure Mode", which was eventually scrapped

“Areas needed to be built with transitions between the two modes in mind and it ended up feeling very disconnected," admits Larsson. "The solution might sound simple but we never really considered it an option until we tried it: We decided the player should be able to control Yoku and the flippers at the same time.”

Under this new philosophy Yoku would always be present, able to grab hold of the ball even during pinball sections, removing the unnatural pinball/platforming transitions via a (“quite funny”) rope that keeps the beetle and the ball together at all times.

A clip of the Yoku's Island Express level design process

Larsson also says that, although working with restrictions and boundaries helps to boost creativity, there were a few frustrating moments where levels had to be re-imagined to work with the pinball mechanics. Most notably, when it came to setting up the cameras in Yoku’s Island Express. According to Larsson, “because of the low amount of control pinball leaves you with compared to other games, stages couldn't be designed with a challenge that has its solution several screens away.”

Villa Gorilla quickly noticed that unlike most platformers, which afford players time to explore an environment and take it all in, pinball is fast-paced and full of random movement. Playing pinball well demands a lot of the player’s attention, and so both the challenges and solutions usually need to be contained and visible on a single screen in Island Express order to be clear.

 A bird's-eye view of a full Yoku's Island Express map filled with interconnected pinball/platforming segments

This then explains why only a few areas in Yoku’s Island Express look like a traditional pinball game. Instead, throughout most of the game players enter wide zones with different sections: there are flippers at the bottom and some hook-shaped paths designed to bring the player back to the zone with ease, fostering opportunities for players to discover new paths and new rewards without bouncing too far afield.

“To be able to use as much of the screen space as possible, the levels needed to be more horizontal than vertical [like traditional pinball tables]," says Larsson. "This proved challenging but ultimately led to some pretty interesting and unique 'tables' in-game.”

Ultimately, while each level in Yoku's Island Express is built on decades-old foundations of pinball and platformer game design, the devs took enough liberties to create accessible and entertaining interconnected "tables" that are unique -- and well worth studying if you're a dev interested in 2D level design.