Hi..I made shoot em up like game.But I have only one ememy which fallows me on screen.But I want to make lots of enemys like each 10 second they will across on screen together 5 or 10 enemys.

 ArrayList<Enemies> enemy = new ArrayList<Enemies>();

 for (Enemies e : enemy) {

        e.draw(g);
    }

is it good creating array list and then showing on screen? And Do I have to make some planing movements thoose enemies in my code ? I want that they vill appear not on same pozition.Like First 5 enemies will come top of screen then the other 5 or 10 enemies will come from left side.. so on.What is best solution for this?