Commercial Games

Scooby-Doo: Monster Mayhem

System Designer | Kuato Studios | Web Browser | June 2022 – November 2022 | Unreleased

Monsters have taken over Crystal Cove, help Scooby & the Gang defend their hometown!

  • Main point of contact (design) from concept to near completion for both internal and external development teams.

  • Championing the creative vision for the game, ensuring it remains true to its roots throughout development.

  • Helping other members of the project team to visualise the end experience and emotions the game is meant to evoke.

  • Understanding the target audience and what motivates them, deriving core pillars that support the overall vision.

  • Creating multiple mechanics/systems working holistically and consistent with the game’s vision and pillars.

  • Creating and maintaining design documentation for reference and briefing, including proof-of-concept presentations, high level design summaries and detailed design schematics.

  • Collaborating with and maintaining frequent communications with programmers, artists, producers, QA, and other roles within Kuato Studios and externally working on the project.
  • Proactively recognising design shortcomings or imbalances in game, proposing intuitive solutions within defined scope.

  • Mapping out the player journey.

  • Balancing in-game items, gameplay difficulty, economy and its meta systems based on the high level goals of different systems in the game.

  • Play testing & providing regular detailed feedback of builds, including UX and UI.

  • Sourcing, editing, and mixing sounds to match style and tone.

  • Understanding and adapting to the commercial and production goals throughout the project and designing within its parameters.

  • Taking part in technical discussions to identify and solve technical issues, including performance and memory usage issues.

  • Supporting localisation efforts.

Project Overview

Target Audience and Timeline

Scooby Doo: Monster Mayhem was a tower defense free to play browser game in development at Kuato Studios over the course of six months, aimed at 6-9yo children. This game was intended to be published on the client’s website, containing several other games targeted at the same age group, so difficulty balancing was key to create an engaging experience that was challenging enough for 9 year olds, whilst ensuring 6 year olds didn’t become frustrated.

Project goals

  • Keep kids engaged with the Scooby-Doo brand
  • Encourage repeat visits to client’s website
  • Creative ways of defeating enemies to ensure the game stays on brand
  • Help drive TV views and ratings through engagement with the game
  • Harness the interest and consider the range of abilities of both the lower and upper end of our target demographic


Due to the short timeline, features and design elements were simplified so existing assets could be re-used. I also extensively researched past show episodes to find visuals that could be re-used or edited to achieve the vision, reducing development efforts.


As the team size varied throughout the project, I helped new team members understand the project, especially aspects that they would be working on and how it fit into the bigger picture. We also collaborated with an external overseas team (production and programming), so I adapted my communication skills to overcome language barriers, while also adapting my workflow to different time-zones.

I had regular meetings with both internal and external teams to provide feedback (playtesting, written and verbal), clarifications on design, and guidance to achieve project vision.


In addition to supporting other disciplines as the designer, I also worked closely with the internal production team throughout the project,

  • supporting efforts to track internal and external tasks
  • adding design notes and references for each task
  • liaising with external producers to solve performance issues
  • communicating with and clarifying design queries from the client, and
  • being involved in scope reduction efforts.

Design and production are two sides of the same coin, as Richard Lemarchand mentions in his book “A Playful Production Process” (a riveting read!), so this was a great opportunity to learn more about game production in practice, while working with different producers. There were many common grounds in terms of thought processes and tools used, such as JIRA, Confluence, and Excel. I once played D&D with a producer who made her character worship JIRA as their one and only god, but that’s a story for another time!

Game Overview

Core experience

Monsters have taken over Crystal Cove, help Scooby & the Gang defend their hometown!”

This seemingly simple sentence was the basis of all concepts that we came up with during the ideation phase, and I kept coming back to it when tailoring features, game plot, theme, and so on. And what better way to have Scoob and the gang defend their spooky hometown than in a tower-defense game?

The Pitch

The exhibits in the Crystal Cove Spook Museum have mysteriously come to life and are escaping the museum to take over the town! Help Scooby & the gang trap the monsters before they cross the barricades. Select a trap based on the number of Scooby Snacks available, and place them on the road. If a monster reaches a gang member, the latter turns blue (of fright) and their lane is spooked. The town goes into a panic frenzy if the whole gang is spooked, prompting you to try again.


Using the core experience and client brief as reference, and after testing out what worked (and what didn’t) in different concepts, I proposed the following features:

  • Use a variety of traps to defend Crystal Cove
    Traps are basically how all monsters are captured in Scooby-Doo, so this one was a no-brainer.
  • Make trap combos for maximum damage
    After mocking up a few layouts and testing on different screen sizes, I proposed adding trap combos, allowing for trap variety while not compromising on grid size (you only need 1 grid slot to make a combo), especially when playing on mobile phones. 
  • Battle a variety of Scooby-Doo monsters with signature attacks
    Having different monsters gave us the opportunity to add variety to each level, while also encouraging repeat visits.
  • Survive monster waves and earn Scooby Snacks to buy and upgrade more traps
    Having an economy system as a base allowed us to balance other systems, such as difficulty progression, more effectively.
  • Plan different defense strategies based on monster type
    This allowed for variety in terms of defense, keeping each playthrough fresh and allowing the player to pick their own play style.

Game Plot

I teamed up with the narrative designer (and fellow Scooby fan) to go through relevant past episodes to find one that would fit with our vision, and also could be plausible in the Scooby-Doo universe. Given that there were four boss monsters in the game, we were keen to find a villain group of four, which proved harder than expected, given that most monsters operate solo. We eventually decided on having the gang’s voice actors disguise as the boss monsters and use the monsters in the museum to destroy Crystal Cove and the gang, in an attempt to become the gang.

It’s all revealed in the end of the game, via a cartoon-strip style sequence which I had the pleasure to mock-up, re-using existing assets and condensing text to meet production goals. 

Game Layout

I experimented with a few layouts, and focused on simplifying elements and making it mobile-friendly with each iteration.

Iteration 1:

A basic layout that explained the concept. Missing trap upgrades, panic traps, a “lives” tracker, and the wave board was difficult to read.

Iteration 3:

Reintroduced wave board as a wave meter to track level progression. Changed spook meter to a spook counter so it’s easier to keep track. Removed trap board to simplify design, popping up instead when you tap on a grid slot. Added panic traps as permanently visible UI. Shrunk museum to allow for more battleground space.

Iteration 2:

Added the Mystery Machine as a trap upgrade center, removed the wave board, and added a spook meter as a “lives” tracker. Gang too small.

Iteration 4:

Experimented with a box instead of circular UI for trap selection. Although UI looked less cluttered, it would overlap with other UI elements if the player chose corner grid slots. It also covered the battleground, making it difficult to keep track of the monsters. The Scooby Snacks counter was also difficult to read in smaller screens.

Lives Indicator and Involving the Gang

After the previous layout iterations, I still felt that the UI could be simplified. I was also keen to make the gang members more involved in the gameplay, instead of simply “being there”, so I suggested using the gang members as live indicators, so if all of them are spooked, you lose the level. Additionally, if a gang member was spooked, their lane would effectively be blocked. This freed up UI space, made the gang more interactive, and provided more space for the Scooby Snack counter.

Trap Board Placement and the Power of Perspective

The brilliant UI designer then suggested re-introducing the trap board, but making it pop up at the bottom of the screen only when you tap on a grid slot – the best of both worlds! He also added a much needed perspective to the battleground, which instantly made it look bigger and more immersive.

We also added a toggle to the trap board, so you can switch between normal and panic traps. Furthermore, the trap board was dynamic, greying out traps that you couldn’t afford, or couldn’t place because something else was on that grid slot.

The “recycler” was also separated from the trap board, to make it clearer to the player that it was a separate feature.

Mystery Machine

Tapping on the Mystery Machine opened the van and allowed players to

  • upgrade base traps if the player had sufficient Scooby Snacks, including a visual to show how upgrading the trap would improve it,
  • test out combos without having to use Scooby Snacks, seeing the trap’s effect on a test monster, and
  • to see the monsters they’ve unlocked.

It drove in between levels, before the monster waves start.


Meet the traps

I collaborated with the design team to come up with a total of 24 traps,

  • Four base traps, equally divided to target either land or air monsters, either attacking or delaying the monster. They could be upgraded to create,
  • Four upgraded traps, also equally divided to target either land or air monsters, either attacking or delaying the monster.
  • Six trap combos, created by placing two base traps on the same grid slot. If you combined an air and a land trap, you could create a combo that targeted both monster types.
  • Six mega trap combos, created by placing two upgraded traps on the same grid slot.
  • Four panic traps, which are free to place but have a cool-down period before it can be reused, and are destroyed after one use. These also target either land or air monsters.

Each trap had different costs, durability, attack score and range values (vertical and horizontal), based on whether they were attackers or delayers, and also what monster type was attacking them, which I balanced to achieve a reasonable difficulty level for the age group. The traps would progressively be more expensive to place, and also more sophisticated with improved stats.


Meet the monsters

I collaborated with the design team to come up with a total of 8 monsters. Monsters were divided between grunt (low and medium), boss, and mega boss types, with different movement patterns, speeds, attack and defense scores, which I balanced to achieve the desired playing experience for the target audience.

Like traps, monster could delay or attack traps. Some boss monsters could also randomly move traps to other lanes, so the players would need to think quick in high-intensity situations. Each boss monster had a unique movement pattern, which adapted based on which lane they chose to go down, and if there were any spooked lanes. These variables made each playthrough different for the player while maintaining difficulty level. 

Game Economy

Scooby Snacks (snacks) was the currency for this game, which you could use to buy or upgrade traps. On successful completion of a level or a monster during a level, the player would be rewarded with snacks, to be used in the next level.

If you ran out of snacks or wanted to change your strategy during a level, you could also sell your traps to recover some snacks. You could also recover snacks if your trap got destroyed, you combined a base and an upgraded trap, and you have traps remaining on the battleground after you’ve completed a level. The amount of snacks you recovered could also vary based on how much damage your trap has taken.

 I balanced all the above variables during development, keeping the snacks fairly abundant to allow for different play styles, and give more space for experimentation. 

Level and Difficulty Progression

Each level was divided into the planning and the active phase.

Planning Phase

This was the period between levels, during which you could spend as long as you want creating your trap setup or use the Mystery Machine. We also added random monster noises and door knocking sounds during this phase, to build a more immersive experience.

Active Phase

This period started once you clicked on the start button, and ended with either you losing or winning the level. This phase was broken to different waves, between which you had a little “breather” moment. We also added thunderstorm and rain effects during this period, to add urgency and differentiate it from the planning phase.

Difficulty progression

In addition to progressively more powerful monsters emerging from the museum in each level, I also proposed adding sewage holes in later levels which monsters could also randomly emerge from to attack the gang. I created mockups, and balanced sewage hole positions for each level. 

Onboarding and Support

I designed onboarding for each feature the player was introduced to during their playthrough. I focused on visuals and using monster pointers to guide the player through the game without using a lot of text. 

I also collaborated with the artist and UI designer to design a range of visuals which the player could cycle through in the pause screen.

Sound Design

I sourced, edited and mixed sounds to be used in-game, matching the desired style and tone. Given that the game was in development, all sounds were selected by imagining how it would play out in-game, using the design document as reference. I also created audio snippets to be used as a guide for how audios for each section of the game should sound like during gameplay. Click here to view a quick breakdown of how audios were categorised based on gameplay requirement.


I listed all texts present in the game with context where needed and where the text shows up, to support localisation efforts.


“Let’s set a trap.”

Based on the brief provided by the client, I concepted a few ideas, designing visual mockups and concept decks to pitch to the wider design team, iterating till we reached the final concept.

One of the concepts, for example, involved picking the “right” objects for each gang member to use as a weapon, like fly swatters to smack creepy crawlies, to stop the monsters emerging from the sea from reaching the good people of Crystal Cove at ground level.

Writing Documentation

I was responsible for writing the design document, to be used by both internal and external development teams as reference throughout the project. This was also used to communicate the deliverables to the client. This was written in a Confluence workspace, making it easier to find relevant sections for individual tasks, version control and to update and maintain the document during development. A PDF version of the GDD can be viewed by clicking here.

Focusing solely on the core experience and features, I also wrote a secondary MVP document to highlight the core elements of the game. This was used as a guide when proposing solutions to meet production scope throughout the project. Click here to read the MVP document.


“There’s a very logical explanation for all this.”

I balanced in-game items, gameplay difficulty, economy and the game’s meta systems. Given that the game was in development, the first pass at balancing was done by imagining how it would play out in-game, using the design document as reference. Further balancing was done once the game was further in development, changing values via exposed scripts and testing until desired player experience was reached.

Click here to view the first pass at balancing the game.


“Let’s do what we do best Scoob, test.”

I regularly playtested builds throughout development, providing feedback based on the design document, client feedback and desired player experience.

Final Thoughts

“And we would have gotten away with it, too, if it weren’t for you meddling kids!”

I thoroughly enjoyed working on this project, and although it wasn’t released, I can’t help but look back in awe at how much the team achieved in a short span of time through sheer determination and resilience (as cheesy as it sounds!).

I recorded a full playthrough during my time playtesting, which you can view below. There are some glaring bugs, such as paintball-dodging monsters, sound levelling, and unpolished intro and end sequences, but hopefully it showcases some of the brilliant work that everyone did on this project.