EYESY on RasPi4 w/ Pisound (step-by-step guide)

Trying to install Eyesy on a RPi 3 with Pisound hat.
Followed the installation walkthrough but now I hit a wall after

git clone https://github.com/okyeron/EYESY_OS_for_RasPi.git Eyesy
cd Eyesy
./deploy.sh

the script stops with

+ sudo apt install -y python-pygame python-liblo python-alsaaudio python-pip libffi-dev nodejs
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Package python-pygame is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

Package python-liblo is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

Package python-pip is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
However the following packages replace it:
  python3-pip

E: Package 'python-pygame' has no installation candidate
E: Package 'python-liblo' has no installation candidate
E: Unable to locate package python-alsaaudio
E: Package 'python-pip' has no installation candidate

Do you have any hints?

Regards,
Tobias.