This is an implementation of the Katarenga game.
Installing Nix is pretty straightforward:
curl https://nixos.org/nix/install | sh
Follow the instructions displayed at the end of the script. You usually need to source a file to access the Nix commands:
source ~/.nix-profile/etc/profile.d/nix.sh
Then you can install katarenga by executing the following command:
nix-env -f https://github.com/Mommessc/clem-pkgs/archive/master.tar.gz -iA katarenga
The installation folder will be accessible via the symbolic link result from where you ran the command.