UX in Candy Crush and the "deceptively complex" world of boosters

• Crush & Tell's first episode features Candy Crush principal UX designer Andrea Serfaty, who talks about player experience and boosters.
• We roll back to episode one for a deeper dive into the role of the UX designer and creating "wow" moments.

Since 2012, King’s Candy Crush Saga has evolved from mobile newcomer to match-3 pioneer with a constant flow of new levels, improved mechanics, and a focus on player experience.

Today, Candy Crush has over 20,000 levels, a collectible system in pins, a narrative-driven mode called Saga Adventures, and more. It’s a broadening of the scope that’s kept Candy Crush fresh.

To find out more about the player experience, how it’s changed through the years, and the role boosters play, we speak with King’s principal UX designer Andrea Serfaty. 

She describes her role as "making sure the whole game feels intuitive and cohesive", achieved through analysing player insights, reviewing new features, and partnering with design and product teams.

"UX is incredibly collaborative, so I work closely with game design, product, UI, art, and engineering," she explains.

"We also rely on data analysts and user researchers to understand how people are playing, and on live ops teams to ensure the broader game environment feels seamless."

Creating a "wow" moment

Serfaty adds that this same range of departments - of core collaborators - is involved when developing boosters; game design, product, UI, art, and engineering all participate in the process, aiming to deliver strong visuals, balanced rules, a clear purpose in the player journey, and smooth engineering.

"That takes close teamwork across many areas," she notes. "A booster is deceptively complex."

Serfaty appeared on the first episode of King’s vodcast-style series Crush & Tell to discuss details of the Super Colour Bomb, a booster that clears two colours of candy from the board, creating bigger cascades than the classic Colour Bomb.

We ask how this more powerful booster affects the player experience, and Serfaty describes the resultant candy explosion as a "wow" moment on the board. She suggests the Super Colour Bomb rewards consistency and skill.

"Players earn it by hitting certain performance or win-streak milestones, and sometimes through special events," she explains.

This ties into the Super Charger, a UX update that aims to give players a greater sense of control. When active, players have a limited amount of time to play with Super Colour Bombs over the regular version, until the time expires or they fail a level.

Serfaty calls this "one of the updates I’m most proud of", because it’s a tool players can actively leverage to make faster progress - and thereby gives them a sense of control.

"Tying the booster to a win streak gives players a clear, motivating goal and creates a strong emotional payoff," she says.

Serfaty adds that not all boosters should have the same power level: this would make the game "flatter". Rather, it’s best for the player experience if different boosters shine in their own situations.

"Some are rarer and more powerful. Others are versatile tools for everyday play. The key is clarity: players should immediately understand when a booster is the right tool for the job."

Serfaty was also involved in this year’s major revamp to Candy Crush’s Fish, which have received a much-needed power boost. Through multiple iterations and a careful alteration of code dating back to 2012, the Fish have become more intelligent and today target more than just jellies.

"I was involved alongside game design and analytics,"  Serfaty shares. "When players feel Fish aren’t behaving predictably, that’s a UX challenge as much as a design challenge. Our role was to understand those expectations and help refine communication and behaviour so the booster feels more intuitive and fair."

We spoke in greater depth with senior product director Alena Rybik about the new Fish 3.0 and making changes which reflect modern game design.

Updates and evolutions

Through the years, another evolution in the Candy Crush player experience is its competitive spirit. Multiple competitions have been introduced like the All Stars tournament, won by Tiago P from Portugal in 2025. He earned a $500,000 prize and a custom diamond ring at the final in LA.

This fifth year of the tournament saw players collect 11.4 trillion candies and complete 2.2bn levels over five weeks.

Serfaty highlights how a diverse range of competitions require "creating tailored experiences that speak to all types of players", from the most engaged to those more casual fans.

"This variety has enriched the overall experience, adding excitement, personal challenge, and moments of calm and disconnect where players need them," she says.

"The inspiration behind these changes was our desire to build a more adapted experience that genuinely resonates with different playstyles and motivations. By designing competitions that meet players where they are, we strengthen their emotional connection to the game and keep their journey feeling fresh and meaningful."

In-game changes are also informed by surveys, social platforms, forums, and app store reviews, with Serfaty personally trawling forums and conducting one-on-one interviews with players too. She takes that feedback - good and bad - to identify UX points to improve.

"While each platform has its own tone, I focus on the patterns that appear across multiple sources and validate them with behavioural data to ensure we are responding in ways that genuinely elevate the player experience," she explains.

For 2026, Serfaty speaks of "constant experimentation and rapid iteration", with goals to continue improving the player experience. Though she can’t go into specifics, Candy Crush will be launching new ideas frequently while "always staying close to how players feel and reacting quickly to what resonates".

More personalised progression, a simplifying of complex systems, and "exciting booster innovations" are all in the cards.