snippet.scala

def updateCity(x: Any) : JsCmd = {
    val (cometName: String, cityId) = Full(x).asA[Map[String, Any]] match {
      case Full(m) => (
        m.get("cometName").getOrElse("No comet Name"),
        m.get("cityId").getOrElse("1")
      )
      case _ => ("No Comet Name", "1")
    }
...
}

untested, but this might work and be a little simpler:

updateCity(x: Any) : JsCmd = {
    val (cometName: String, cityId) = x match {
      case m: Map[String, Any]] => (
        m.get("cometName").getOrElse("No comet Name"),
        m.get("cityId").getOrElse("1")
      )
      case _ => ("No Comet Name", "1")
    }
...

or even

def updateCity(x: Any) : JsCmd = {
    val (cometName: String, cityId) = Full(x).asA[Map[String, Any]].map { m =>
      (
        m.get("cometName").getOrElse("No comet Name"),
        m.get("cityId").getOrElse("1")
      )
    } openOr ("No Comet Name", "1")
...
}