diff --git a/gamepizero.sh b/gamepizero.sh
new file mode 100644
index 0000000..040e319
--- /dev/null
+++ b/gamepizero.sh
@@ -0,0 +1,180 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# ==========================================================
+# GamePiZero Installer / Updater
+# Raspberry Pi OS Lite / Headless
+# ==========================================================
+
+APP_NAME="gamepizero"
+
+ZIP_URL="https://example.com/gamepizero.zip"
+
+INSTALL_DIR="/opt/gamepizero"
+TMP_DIR="/tmp/gamepizero-install"
+
+EXECUTABLE_PATH="/opt/gamepizero/GamePiZero.App"
+
+SERVICE_NAME="gamepizero.service"
+SERVICE_FILE="/etc/systemd/system/${SERVICE_NAME}"
+
+REBOOT_REQUIRED=0
+
+# ==========================================================
+# Prüfung
+# ==========================================================
+
+if [[ "${EUID}" -ne 0 ]]; then
+  echo "Bitte mit sudo ausführen:"
+  echo "  sudo ./gamepizero.sh install"
+  echo "  sudo ./gamepizero.sh update"
+  exit 1
+fi
+
+ACTION="${1:-}"
+
+case "${ACTION}" in
+  install|update)
+    ;;
+  *)
+    echo "Verwendung:"
+    echo "  sudo ./gamepizero.sh install"
+    echo "  sudo ./gamepizero.sh update"
+    exit 1
+    ;;
+esac
+
+# ==========================================================
+# Funktionen
+# ==========================================================
+
+log() {
+  echo "[INFO] $1"
+}
+
+error() {
+  echo "[ERROR] $1" >&2
+}
+
+install_dependencies() {
+  log "Installiere benötigte Pakete..."
+
+  apt-get update
+  apt-get install -y curl unzip raspi-config
+}
+
+enable_i2c() {
+  log "Prüfe I²C..."
+
+  if command -v raspi-config >/dev/null 2>&1; then
+    if raspi-config nonint get_i2c | grep -q "0"; then
+      log "I²C ist bereits aktiviert."
+    else
+      log "Aktiviere I²C..."
+      raspi-config nonint do_i2c 0
+      REBOOT_REQUIRED=1
+    fi
+  else
+    error "raspi-config nicht gefunden. I²C konnte nicht automatisch aktiviert werden."
+  fi
+}
+
+stop_service_if_exists() {
+  if systemctl list-unit-files | grep -q "^${SERVICE_NAME}"; then
+    log "Stoppe bestehenden Dienst..."
+    systemctl stop "${SERVICE_NAME}" || true
+  fi
+}
+
+download_zip() {
+  log "Lade Anwendung herunter..."
+
+  rm -rf "${TMP_DIR}"
+  mkdir -p "${TMP_DIR}"
+
+  curl -fL "${ZIP_URL}" -o "${TMP_DIR}/${APP_NAME}.zip"
+}
+
+extract_app() {
+  log "Installiere Anwendung nach ${INSTALL_DIR}..."
+
+  mkdir -p "${INSTALL_DIR}"
+  unzip -o "${TMP_DIR}/${APP_NAME}.zip" -d "${INSTALL_DIR}"
+
+  if [[ ! -f "${EXECUTABLE_PATH}" ]]; then
+    error "Executable wurde nicht gefunden:"
+    error "${EXECUTABLE_PATH}"
+    exit 1
+  fi
+
+  chmod +x "${EXECUTABLE_PATH}"
+
+  # App läuft als root, daher Dateien root:root
+  chown -R root:root "${INSTALL_DIR}"
+
+  rm -rf "${TMP_DIR}"
+}
+
+install_service() {
+  log "Erstelle systemd-Dienst..."
+
+  cat > "${SERVICE_FILE}" <<EOF
+[Unit]
+Description=GamePiZero
+After=network-online.target
+Wants=network-online.target
+
+[Service]
+Type=simple
+WorkingDirectory=${INSTALL_DIR}
+ExecStart=${EXECUTABLE_PATH}
+Restart=always
+RestartSec=5
+
+# Die App läuft bewusst als root
+User=root
+Group=root
+
+Environment=DOTNET_SYSTEM_GLOBALIZATION_INVARIANT=1
+
+[Install]
+WantedBy=multi-user.target
+EOF
+
+  systemctl daemon-reload
+  systemctl enable "${SERVICE_NAME}"
+  systemctl restart "${SERVICE_NAME}"
+}
+
+show_status() {
+  log "Dienststatus:"
+  systemctl --no-pager status "${SERVICE_NAME}" || true
+}
+
+# ==========================================================
+# Ablauf
+# ==========================================================
+
+log "Aktion: ${ACTION}"
+
+install_dependencies
+enable_i2c
+
+if [[ "${ACTION}" == "update" ]]; then
+  stop_service_if_exists
+fi
+
+download_zip
+extract_app
+install_service
+show_status
+
+echo
+echo "Fertig."
+
+if [[ "${REBOOT_REQUIRED}" == "1" ]]; then
+  echo
+  echo "I²C wurde aktiviert."
+  echo "Ein Reboot ist empfohlen:"
+  echo "  sudo reboot"
+fi
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