Time for action – summoning the zombies

1. Add a new class called Enemy to the Gemstone Hunter project.

2. Add the following Imports directive to the top of the Enemy class file:

   Imports Tile_Engine

3. Add an Inherits line to derive the Enemy class from GameObject:

   Public Class Enemy
       Inherits GameObject

4. Add declarations for the Enemy class:

   #Region "Declarations"
   Private _fallSpeed As Vector2 = New Vector2(0, 20)
   Private _walkSpeed As Single = 60
   Private _facingLeft As Boolean = True
   #End Region

5. Add a property to the Enemy class:

   #Region "Properties"
   Public Property Dead As Boolean
   #End Region

6. Add a constructor for the Enemy class:

   #Region "Constructor"
   Public Sub New(
       content As ContentManager, 
       cellX As Integer,
       cellY As Integer)
   
       _animations.Add("idle",
           New AnimationStrip(
               content.Load(Of Texture2D)(
                   "Textures\Sprites\MonsterC\Idle"),
               48, 
               "idle"))
       _animations("idle").LoopAnimation = True
   
       _animations.Add("run",
      ...