diff --git a/.circleci/test-deploy.yml b/.circleci/test-deploy.yml
index c10fca6..c213b9d 100644
--- a/.circleci/test-deploy.yml
+++ b/.circleci/test-deploy.yml
@@ -32,6 +32,18 @@ pre-steps:
 
           # Move the demo project to the project folder
           mv ../Unity2D-Demo-Game-CI-CD ./Unity2D-Demo-Game-CI-CD    
+  custom-build-method: &custom-build-method
+    - run:
+        name: "Clone the demo project"
+        command: |
+          # Clone the demo project with custom build method
+          git clone --branch custom-build-method --single-branch https://github.com/EricRibeiro/Unity2D-Demo-Game-CI-CD.git ../Unity2D-Demo-Game-CI-CD
+
+          # Clone the Unity orb
+          git clone https://github.com/game-ci/unity-orb.git .
+
+          # Move the demo project to the project folder
+          mv ../Unity2D-Demo-Game-CI-CD ./Unity2D-Demo-Game-CI-CD
 
 workflows:
   test-build:
@@ -281,6 +293,41 @@ workflows:
           filters: *filters
           context: orb-testing-unity
           pre-steps: *mono
+      - unity/build:
+          name: "build-with-custom-method-windows"
+          step-name: "Build with custom method in Windows"
+          unity-license-var-name: "UNITY_ENCODED_LICENSE_2021"
+          unity-username-var-name: "UNITY_USERNAME"
+          unity-password-var-name: "UNITY_PASSWORD"
+          executor:
+            name: "unity/windows-2019"
+            size: "large"
+            editor_version: "2021.3.2f1"
+            target_platform: "windows-il2cpp"
+          project-path: "Unity2D-Demo-Game-CI-CD/src"
+          build-target: StandaloneWindows64
+          build-method: "MyCustomBuildCommand.MyCustomBuildMethod"
+          custom-parameters: "-customParam1 potato -customParam2 tomato -customParam3 $CIRCLE_WORKFLOW_ID -DetailedBuildReport"
+          filters: *filters
+          context: orb-testing-unity
+          pre-steps: *custom-build-method
+      - unity/build:
+          name: "build-with-custom-method-osx"
+          step-name: "Build with custom method in macOS"
+          unity-license-var-name: "UNITY_ENCODED_LICENSE_2021"
+          unity-username-var-name: "UNITY_USERNAME"
+          unity-password-var-name: "UNITY_PASSWORD"
+          executor:
+            name: "unity/macos"
+            editor_version: "2021.3.1f1"
+            resource_class: "large"
+          project-path: "Unity2D-Demo-Game-CI-CD/src"
+          build-target: StandaloneOSX
+          build-method: "MyCustomBuildCommand.MyCustomBuildMethod"
+          custom-parameters: "-customParam1 potato -customParam2 tomato -customParam3 $CIRCLE_WORKFLOW_ID -DetailedBuildReport"
+          filters: *filters
+          context: orb-testing-unity
+          pre-steps: *custom-build-method
 
       - orb-tools/pack:
           filters: *filters
@@ -304,6 +351,8 @@ workflows:
             - build-ios
             - build-tvOS
             - build-without-artifacts
+            - build-with-custom-method-windows
+            - build-with-custom-method-osx
           context: orb-publishing
           filters:
             branches:
diff --git a/src/commands/build.yml b/src/commands/build.yml
index 92d7b20..041e98c 100644
--- a/src/commands/build.yml
+++ b/src/commands/build.yml
@@ -51,6 +51,21 @@ parameters:
     type: string
     default: "10m"
     description: Elapsed time the command can run without output.
+  build-method:
+    type: string
+    default: ""
+    description: |
+      The method used as argument for the Unity CLI "executeMethod" parameter.
+      It must be a valid path to a static method and the class exist in the Assets/Editor directory.
+      If left empty, the default build method will be used.
+  custom-parameters:
+    type: string
+    default: ""
+    description: |
+      Additional arguments for the Unity CLI.
+      Use it to pass arguments defined on your custom "build-method" or Unity's build options. Environment variables are supported.
+      The parameters must be separated by space and must be in the format "-key value" or "-key" for booleans.
+      Example: "-customArg1 WebGL -EnableHeadlessMode -customArg2 $CIRCLE_WORKFLOW_ID".
 
 steps:
   - run:
@@ -61,6 +76,8 @@ steps:
         PARAM_BUILD_TARGET: << parameters.build-target >>
         PARAM_PROJECT_PATH: << parameters.project-path >>
         PARAM_COMPRESS: << parameters.compress >>
+        PARAM_BUILD_METHOD: << parameters.build-method >>
+        PARAM_CUSTOM_PARAMETERS: << parameters.custom-parameters >>
         SCRIPT_BUILD_WINDOWS: << include(scripts/windows/build.sh) >>
         SCRIPT_BUILD_LINUX: << include(scripts/linux/build.sh) >>
         SCRIPT_BUILD_MACOS: << include(scripts/macos/build.sh) >>
diff --git a/src/jobs/build.yml b/src/jobs/build.yml
index 7d5c516..9e3d49d 100755
--- a/src/jobs/build.yml
+++ b/src/jobs/build.yml
@@ -73,6 +73,21 @@ parameters:
     type: string
     default: "20m"
     description: Elapsed time the command can run without output.
+  build-method:
+    type: string
+    default: ""
+    description: |
+      The method used as argument for the Unity CLI "executeMethod" parameter.
+      It must be a valid path to a static method and the class exist in the Assets/Editor directory.
+      If left empty, the default build method will be used.
+  custom-parameters:
+    type: string
+    default: ""
+    description: |
+      Additional arguments for the Unity CLI.
+      Use it to pass arguments defined on your custom "build-method" or Unity's build options. Environment variables are supported.
+      The parameters must be separated by space and must be in the format "-key value" or "-key" for booleans.
+      Example: "-customArg1 WebGL -EnableHeadlessMode -customArg2 $CIRCLE_WORKFLOW_ID".
 
 executor: << parameters.executor >>
 
@@ -93,6 +108,8 @@ steps:
       store-artifacts: <<parameters.store-artifacts>>
       compress: <<parameters.compress>>
       no_output_timeout: << parameters.no_output_timeout>>
+      build-method: <<parameters.build-method>>
+      custom-parameters: <<parameters.custom-parameters>>
   - when:
       condition: <<parameters.return-license>>
       steps:
diff --git a/src/scripts/build.sh b/src/scripts/build.sh
index d44b919..89e2327 100644
--- a/src/scripts/build.sh
+++ b/src/scripts/build.sh
@@ -1,4 +1,5 @@
 #!/usr/bin/env bash
+# shellcheck disable=SC2034
 
 readonly base_dir="${CIRCLE_WORKING_DIRECTORY/\~/$HOME}"
 readonly unity_project_full_path="$base_dir/$PARAM_PROJECT_PATH"
@@ -9,9 +10,17 @@ eval "$SCRIPT_UTILS"
 # Detect host OS.
 detect-os
 
-# Copy builder to project directory.
-mkdir -p "$unity_project_full_path/Assets/Editor/"
-printf '%s\n' "$DEPENDENCY_UNITY_BUILDER" > "$unity_project_full_path/Assets/Editor/BuildCommand.cs"
+# Copy builder to project directory if a custom isn't specified.
+build_method="$PARAM_BUILD_METHOD"
+if [ -z "$PARAM_BUILD_METHOD" ]; then
+  printf '%s\n' "The \"build-method\" parameter is empty. Falling back to the default build script."
+  mkdir -p "$unity_project_full_path/Assets/Editor/"
+  printf '%s\n' "$DEPENDENCY_UNITY_BUILDER" > "$unity_project_full_path/Assets/Editor/BuildCommand.cs"
+  build_method="BuildCommand.PerformBuild"
+fi
+
+# Expand custom parameters, if any.
+custom_parameters="$(eval echo "$PARAM_CUSTOM_PARAMETERS")"
 
 # If "build_name" is blank, use the build target.
 if [ -z "$PARAM_BUILD_NAME" ]; then PARAM_BUILD_NAME="$PARAM_BUILD_TARGET"; fi
diff --git a/src/scripts/macos/build.sh b/src/scripts/macos/build.sh
index 828dd2b..3501d39 100644
--- a/src/scripts/macos/build.sh
+++ b/src/scripts/macos/build.sh
@@ -1,9 +1,8 @@
 #!/bin/false
 # shellcheck shell=bash
-# shellcheck disable=SC2154
+# shellcheck disable=SC2048,SC2154,SC2086
 
 readonly build_path="$unity_project_full_path/Builds/$PARAM_BUILD_TARGET"
-
 mkdir -p "$build_path"
 
 set -x
@@ -16,9 +15,10 @@ set -x
   -buildTarget "$PARAM_BUILD_TARGET" \
   -customBuildTarget "$PARAM_BUILD_TARGET" \
   -customBuildPath "$build_path/$PARAM_BUILD_NAME" \
-  -executeMethod "BuildCommand.PerformBuild" \
+  -executeMethod "$build_method" \
   -buildVersion "1.0.0" \
-  -logfile /dev/stdout
+  -logfile /dev/stdout \
+  $custom_parameters # Needs to be unquoted. Otherwise it will be treated as a single parameter.
 set +x
 
 if [ "$PARAM_COMPRESS" -eq 1 ]; then
diff --git a/src/scripts/windows/build.sh b/src/scripts/windows/build.sh
index 74e1bb0..fc2428d 100644
--- a/src/scripts/windows/build.sh
+++ b/src/scripts/windows/build.sh
@@ -22,11 +22,15 @@ docker exec "$CONTAINER_NAME" powershell mkdir C:/build
 # Add the build target and build name in the environment variables.
 docker exec "$CONTAINER_NAME" powershell "[System.Environment]::SetEnvironmentVariable('BUILD_NAME','$PARAM_BUILD_NAME', [System.EnvironmentVariableTarget]::Machine)"
 docker exec "$CONTAINER_NAME" powershell "[System.Environment]::SetEnvironmentVariable('BUILD_TARGET','$PARAM_BUILD_TARGET', [System.EnvironmentVariableTarget]::Machine)"
+docker exec "$CONTAINER_NAME" powershell "[System.Environment]::SetEnvironmentVariable('BUILD_METHOD','$build_method', [System.EnvironmentVariableTarget]::Machine)"
+docker exec "$CONTAINER_NAME" powershell "[System.Environment]::SetEnvironmentVariable('CUSTOM_PARAMS','$custom_parameters', [System.EnvironmentVariableTarget]::Machine)"
 
 # Build the project
 # Versioning of the project needs work. This is how it's done in the GHA:
 # https://github.com/game-ci/unity-builder/blob/main/src/model/versioning.ts
-docker exec "$CONTAINER_NAME" powershell '& "C:\Program Files\Unity\Hub\Editor\*\Editor\Unity.exe" -batchmode -quit -nographics -projectPath $Env:PROJECT_PATH -buildTarget $Env:BUILD_TARGET -customBuildTarget $Env:BUILD_TARGET -customBuildName $Env:BUILD_NAME -customBuildPath "C:/build/" -executeMethod BuildCommand.PerformBuild -logfile | Out-Host'
+set -x
+docker exec "$CONTAINER_NAME" powershell '& "C:\Program Files\Unity\Hub\Editor\*\Editor\Unity.exe" -batchmode -quit -nographics -projectPath $Env:PROJECT_PATH -buildTarget $Env:BUILD_TARGET -customBuildTarget $Env:BUILD_TARGET -customBuildName $Env:BUILD_NAME -customBuildPath "C:/build/" -executeMethod $Env:BUILD_METHOD $Env:CUSTOM_PARAMS.split() -logfile | Out-Host'
+set +x
 
 # Compress the build folder.
 docker exec "$CONTAINER_NAME" powershell 'tar -czf "C:/$Env:BUILD_NAME-$Env:BUILD_TARGET.tar.gz" -C "C:/build" .'