McKinsey Solve Ocean Cleanup Game (2024)

the image shows a sea turtle as the cover for an article on the mckinsey ocean cleanup game which is part of the solve game

Last Updated on July 8, 2024

The McKinsey Problem Solving Game (PSG) or simply “McKinsey Solve” has made waves since its introduction in late 2019 in the recruiting process of the Firm. It’s been a benchmark for testing analytical and problem-solving skills in potential consultants in a gamified environment.

Since we launched the first global Solve Guide at the end of 2019, we have been monitoring the development closely, collecting insights from a few hundred test-takers over the last few years. Initially, McKinsey and Imbellus changed the game quite frequently with minor iterations and tests of new additional games. The main game lineup, however, has been relatively steady over the years.

The biggest change came in March 2023, when the Plant Defense Game was replaced by the Red Rock Simulation.

Now, 1.5 years later, it seems that McKinsey is beta testing a new game called “Ocean Cleanup” or “Ocean Treatment.” This game not only challenges players to think critically and strategically but also introduces another environmentally significant theme of ocean plastic cleanup.

In this article, we’ll delve into what makes the McKinsey Ocean Cleanup game a notable addition to the PSG lineup, exploring its structure, user experiences, and potential impact on future tests.

The key thing for you to remember at this stage: It is likely not used as an evaluation device yet but in beta testing. That means that it will not be used to make any hiring decisions. You should still focus on the Ecosystem and Red Rock Simulation.

Overview of McKinsey Ocean Cleanup Game

What is the McKinsey Ocean Cleanup Game?

The McKinsey Ocean Cleanup game is the latest addition to the McKinsey Problem Solving Game (PSG) series, designed to test candidates’ analytical and problem-solving abilities in a unique and engaging way. This 20-minute test requires players to choose between 20 different microbes, each with specific characteristics such as heat resistance, photosensitivity, pH levels, color, and reactivity. The primary objective is to create bond chains using these microbes to effectively clean plastic from designated areas of the ocean.

In this game, players are presented with two areas of the ocean that need to be cleansed of plastic. The task involves a two-phase process for each area:

  1. Selection of 10 Microbes: Players must select 10 microbes that match the specific parameters (e.g., rigidity, liquidity, size) and characteristics (e.g., hot, hydrophilic) of the area being cleaned. This phase requires careful consideration of the environmental conditions and the attributes of the microbes to ensure they are suitable for the task.
  2. Choosing 3 Microbes: From the 10 selected microbes, players then choose 3 that will form the bond chains to clean the plastic. The chosen microbes’ average parameters must closely align with the average of the remaining 7 microbes, ensuring an effective and balanced solution.

Key Details of the Ocean Treatment Game


The McKinsey Ocean Cleanup game is designed to be a concise and focused test, lasting 20 minutes. Within this time frame, candidates are expected to complete the two-phase process of selecting and utilizing microbes to cleanse specific areas of the ocean.


The primary objective of the McKinsey Ocean Cleanup game is to strategically choose and combine microbes to create effective bond chains that clean plastic from designated ocean areas. Candidates must consider various characteristics of the microbes, such as heat resistance, photosensitivity, pH levels, color, and reactivity, to ensure the most efficient and balanced solution.

Placement in the Test Sequence

Currently, the McKinsey Ocean Cleanup game is positioned after the Ecosystem and Red Rock games in the McKinsey Solve test sequence. Candidates first complete the Ecosystem game, followed by the Red Rock game, and then proceed to the Ocean Cleanup game.

Launch Status

The McKinsey Ocean Cleanup game is currently in its beta testing phase. Early testers have been given the opportunity to try out the game and provide feedback on its functionality and user experience. Based on this feedback, McKinsey will make any necessary adjustments before the game is officially launched. The formal rollout of the McKinsey Ocean Cleanup game is not guaranteed. McKinsey and Imbellus have tested quite a few games in the past that never made it past the testing stage.

Game Structure and Phases

Selection of 10 Microbes for Each Area

Explanation of the Selection Process

The first phase of the McKinsey Ocean Cleanup game involves selecting 10 microbes from a pool of 20. This selection process requires players to analyze and match the microbes to the specific conditions of the area of the ocean they are trying to clean. The aim is to choose microbes that are best suited to thrive and function in the given environmental parameters.

Parameters and Characteristics

Each area of the ocean is defined by a set of parameters and characteristics:

  • Parameters: These are numerical values that describe the conditions of the area, such as rigidity, liquidity, and size. For example, an area might have a rigidity range of 4-7.
  • Characteristics: These are binary attributes that are either present or not, such as being hot or hydrophilic.

Players must carefully evaluate the microbes to ensure they match the parameters and characteristics of the area. This involves reading through the microbes’ descriptions and selecting those that fall within the specified ranges and possess the necessary attributes.

Choosing 3 Microbes for Each Area

Explanation of the Selection Criteria

After selecting 10 microbes that match the area’s conditions, the next phase involves narrowing this selection down to 3 microbes. The key criteria for this selection are:

  • The average values of the selected 3 microbes should be as close as possible to the average of the remaining 7 microbes. This balance is crucial for ensuring the effectiveness of the solution.

This phase is more analytical and requires a strategic approach to ensure that the selected microbes work well together and are balanced in relation to the ones not chosen.

Tips for Optimal Selection

  1. Use tools: Utilize tools like Excel to quickly calculate averages and compare values. This can help in making more precise selections.
  2. Understand the rules: Make sure to thoroughly understand the game’s rules and criteria for selection. Misinterpreting these can lead to suboptimal choices.
  3. Balance parameters: Focus on selecting microbes that balance out the parameters effectively. Avoid extreme values that can skew the averages.
  4. Review characteristics: Ensure that the selected microbes not only match the numerical parameters but also the required characteristics. Overlooking these can impact the solution’s success.

Follow these steps and tips to navigate the McKinsey Ocean Cleanup game more effectively, making informed decisions that align with the game’s objectives. This structured approach helps in developing a solution that is both efficient and effective in cleaning the ocean areas. The more people know about the game and how to attack it, the more score inflation we will see.

User Experiences and Feedback

Initial Surprise

Testers were taken by surprise when the McKinsey Ocean Cleanup game was introduced unexpectedly after the familiar Ecosystem and Red Rock games. Many candidates anticipated the usual two-part sequence and were caught off guard when the site refreshed with a third test. This sudden addition required a quick mental shift. The initial surprise underscores the importance of staying adaptable and composed during the test process.

Learning Curve

The introduction of the McKinsey Ocean Cleanup game brought with it a steep learning curve. Testers reported challenges with the instructions and the game interface, describing them as somewhat clunky and unintuitive. One user mentioned spending at least 20 minutes in the tutorial, re-reading the instruction passages due to their complexity. This experience highlights the need for clear and straightforward guidance to help candidates grasp the game mechanics quickly.

This is something we have observed in the past where candidates we talked to constantly reported issues with the UI and UX of previous games.


Despite the initial hurdles, many testers found the McKinsey Ocean Cleanup game enjoyable once they got the hang of it. Compared to the Ecosystem game, several users felt that the Ocean Cleanup game was more engaging and less complicated. The game was described as fun, with one tester noting that it felt more like a game than a test.

We have adjusted our guide to include strategies for the Ocean Treatment Game. For more information, see below.

McKinsey Solve Game Guide

(261 customer reviews)
Original price was: $89.00.Current price is: $54.00.

Elevate your Solve Game score with the original game guide, a 14-part video course, an Excel Solver tool, and Red Rock practice tests. Trusted by more than 8,500 customers from 70+ countries since November 2019.

What to Do If You Encounter The Ocean Cleanup Game

Staying Calm

When faced with the unexpected McKinsey Ocean Cleanup game, it is crucial to stay calm and composed. Here are some tips for maintaining your composure:

  • Stay focused: Remind yourself that you have prepared for problem-solving scenarios and that this is just another opportunity to demonstrate your skills.
  • Break it down: Approach the game step-by-step. Focus on one task at a time rather than becoming overwhelmed by the entire challenge.
  • Stay prepared: Have an Excel file open to help you with the analysis.

Following Instructions Carefully

Understanding and following the game’s instructions is essential for success:

  • Read thoroughly: Take your time to read through the instructions carefully. Misunderstanding the rules can lead to mistakes. Use all the time you need in the untimed tutorial to familiarize yourself with the new game.
  • Take notes: Jot down key points from the instructions that you can refer back to during the game.
  • Practice patience: If the instructions seem complex, read them multiple times until you fully grasp the requirements.

Providing Feedback

As the McKinsey Ocean Cleanup game is in its beta testing phase, your feedback will be requested at the end.

  • Be honest: Provide candid feedback about your experience, including any difficulties you encountered with the instructions or interface.
  • Detail specific issues: Highlight specific areas where you faced challenges, such as unclear instructions or technical glitches.
  • Suggest improvements: Offer constructive suggestions on how the game can be enhanced to improve clarity and user experience.

The McKinsey Ocean Cleanup game represents a significant addition to the McKinsey Problem Solving Game (PSG) series, reflecting McKinsey’s commitment to integrating real-world issues into their assessment framework. This game not only tests candidates’ analytical and problem-solving skills but also raises awareness about environmental sustainability.

Our McKinsey Solve Game Guide

The original and most comprehensive guide from former McKinsey consultants with

87% pass rate in the Solve Game*

Your benefit

  • Crack each of the 6 games with our proprietary guide and video insights on the exact steps and strategies
  • Focus on the current 3 games of the Solve: Ecosystem, Red Rock, Ocean Treatment and Cleanup
  • Score high with tailored strategies and gameplay walkthroughs based on successful test-taker feedback
  • Focus on what matters most, and don’t waste time in your preparation with proven ways to master all skills
  • Prepare with 100% confidence for the latest changes in the scenarios with our constant update policy and free 1-year access guarantee
  • Practice the quantitative reasoning part of the Red Rock game with full-length 6 practice tests
  • Includes a free 14-page McKinsey Interview Primer, giving you essential tips on how to prepare for the case and the PEI
  • FREE BONUS: A 10% discount on the Solve Game Simulation by MConsultingPrep
  • *based on customer feedback from Nov 23 – Jan 24

Latest update: July 2024 (includes strategies for the new Ocean Cleanup and Treatment Game)

Our Credentials

  • Helped 8500+ students from more than 70 countries since November 2019
  • Based on 500+ test-taker interviews since the inception of the game, expert game designer input, and our McKinsey experience
  • Includes a 161-page guide, automated Excel templates for the Ecosystem creation, and 14 concise videos on the gameplay and winning strategies (1 hour in total to cover everything you need in the shortest time possible), 6 Red Rock practice tests for the Study and the Case section
  • 100% proprietary information
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McKinsey Solve Game Guide (Imbellus) 21st Edition

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