This service file worked for me... Note how it starts after After=sound.target
[Unit]
Description=FireHouse Game
After=sound.target
[Service]
Type=simple
Environment="DISPLAY=:0"
Environment="XAUTHORITY=/home/pi/.Xauthority"
ExecStart=/usr/bin/python3 /home/pi/FireGame/fire_game.py
Restart=on-abort
KillMode=process
SendSIGHUP=nos
[Install]
WantedBy=graphical.target
