diff --git a/.github/workflows/check_code.yml b/.github/workflows/check_code.yml
new file mode 100644
index 0000000..f7c002a
--- /dev/null
+++ b/.github/workflows/check_code.yml
@@ -0,0 +1,12 @@
+name: check_code
+on: pull_request
+jobs:
+  lint_python:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-python@v2
+      - run: pip install --upgrade pip wheel
+      - run: pip install black isort
+      - run: black --check --diff --line-length 79 .
+      - run: isort --check-only --line-length 79 --profile black .
diff --git a/README.md b/README.md
index 9bfe013..450fae6 100644
--- a/README.md
+++ b/README.md
@@ -52,6 +52,11 @@ Overcooked-Demo can dynamically load pre-trained agents provided by the user. In
 
 If a more complex or custom loading routing is necessary, one can subclass the `OvercookedGame` class and override the `get_policy` method, as done in [DummyOvercookedGame](server/game.py#L420). Make sure the subclass is properly imported [here](server/app.py#L5)
 
+## Use the human vs. human game mode.
+
+With the Overcooked demo you can test the interaction between two human players. To do this, select the human keyboard input for both players and click on "Create Game", it will display "Waiting for game to start". Open another tab and navigate to http://localhost/psyturk to start the game.
+The first user can be controlled from the same page, the other user from another tab (http://localhost/psiturk).
+
 ## Updating Overcooked_ai
 This repo was designed to be as flexible to changes in overcooked_ai as possible. To change the branch used, use the `OVERCOOKED_BRANCH` environment variable shown above.
 
@@ -70,4 +75,4 @@ Basic game settings can be configured by changing the values in [config.json](se
 
 ## Legacy Code
 
-For legacy code compatible with the Neurips2019 submission please see [this](https://github.com/HumanCompatibleAI/overcooked-demo/tree/legacy) branch of this repo. 
\ No newline at end of file
+For legacy code compatible with the Neurips2019 submission please see [this](https://github.com/HumanCompatibleAI/overcooked-demo/tree/legacy) branch of this repo. 
diff --git a/server/requirements.txt b/server/requirements.txt
index dfcae0f..a9810c7 100644
--- a/server/requirements.txt
+++ b/server/requirements.txt
@@ -1,17 +1,18 @@
 certifi==2020.6.20
-click==7.1.2
+click==8.0
 dnspython==1.16.0
 dill==0.3.2
-Flask==1.1.2
+Flask==2.1.0
 Flask-SocketIO==4.3.0
 greenlet==0.4.16
-itsdangerous==1.1.0
-Jinja2==2.11.2
-MarkupSafe==1.1.1
+itsdangerous==2.0
+Jinja2==3.1.0
+MarkupSafe==2.0
 monotonic==1.5
 python-engineio==3.13.0
 python-socketio==4.6.0
 six==1.15.0
-Werkzeug==1.0.1
+Werkzeug==2.0.3
 tensorflow==2.0.3
 requests==2.23.0
+protobuf==3.19