从零开始手把手教你使用javascript+canvas开发一个塔防游戏03敌人一波一波的出

//出敌人
    initEnemy : function(){
        if(Game.missionLazy > 0){
            Game.missionLazy -= 20;
            return false;
        }
        if(Game.enemyLazy > 0){
            Game.enemyLazy -= 20;
            return false;
        }
        else{
            Game.enemyLazy = Game.enemyTime;
        }
        if(Game.missionEnemy > 20){
            Game.missionEnemy = 1;
            Game.mission += 1;
            Info.updateMission();
            Game.missionLazy = Game.missionTime;
            if(Game.mission >= 20){
                Game.initEnemy = function(){
                    if(Game.enemyList.length <= 0)Game.win();
                };
                return false;
            }
            return false;
        }
        Game.missionEnemy += 1;
        //新增一个敌人
        var enemy = new Enemy(Game.canvasList.main,Game.imgList.enemy_img,Game.mission,55,0,40,40);
        enemy.num = Game.mission*20+Game.missionEnemy;
        Game.enemyList.push(enemy);
    }