var chance, _x, _y;

for(i = -64; i < room_width + 64; i += 32)
{
    for(j = room_height; j > -64; j -= 32)
    {
        o = instance_create(i, j, block)
        o.type = 1
        chance[1] = choose(-1, 1)
        chance[2] = irandom(10)
        if chance[1]
        {
            if chance[2] == 10
            {
                instance_create(i, j, destroyer)
            }
        }
    }
}

while 1
{
    _x = random(room_width)
    _y = random(room_height)
    if !collision_rectangle(_x - 32, _y - 32, _x + 32, _y, solid, 1, 0)
    {
        instance_create(_x, _y, player)
        break
    }
}