visual basic game player wont move - vb.net

Question

For a school project I am making a simple game were zombie's walk straight down and try to attack the players base (it is kinda like space invaders and planets versus zombies). however my player has stopped moving when I press D or A, when I try to play the game. I will post my code. can somebody help make my player move side to side?.
Public Class Form2
Dim Player_Health As Integer = 10
Dim Player_Max_Health As Integer = 100
Dim Player_X_Speed_Moving As Integer = 0
Dim Player_Potential_X_Speed As Integer = 10
Private Sub Form2_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles Me.KeyDown
If e.KeyCode = Keys.A Then
Player_X_Speed_Moving = -Player_Potential_X_Speed
End If
If e.KeyCode = Keys.D Then
Player_X_Speed_Moving = Player_Potential_X_Speed
End If
End Sub
Private Sub Form2_KeyUp(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles Me.KeyUp
If e.KeyCode = Keys.A Then
Player_X_Speed_Moving = 0
End If
If e.KeyCode = Keys.D Then
Player_X_Speed_Moving = 0
End If
End Sub
Private Sub Form2_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim bmp As Bitmap = Bitmap.FromFile("C:\Users\Kevin Welch\Documents\Visual Studio 2010\Projects\Zom-b\Zom-b\My Project\Res\Spr\Player1.bmp")
bmp.MakeTransparent(Color.White) ' magenta in bitmap will be transparent
PictureBox1.Image = bmp
Timer1.Enabled = True
End Sub
Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
Call MovePlayer()
End Sub
Private Sub MovePlayer()
PictureBox1.Left += Player_X_Speed_Moving
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Form1.Show()
Me.Hide()
End Sub
End Class

Answer 1

My guess would be that the form's message queue is getting backed up with key down events and your Tick event is having trouble keeping up. Most window UI systems use a single thread that responds to messages that are pumped to them such as key down/up, mouse movements, and clicks. If the UI thread is busy, your Tick event will have to wait since it runs on the same thread. Many games have a game loop that processes window events along with processing game logic and graphics rendering. I would recommend look into using the XNA Framework since it handles most of that stuff for you.