How to loop bitmaps going down a form without using an array

If I try the following in my timer nothing changes. When the dialog box loads it shouldn't really matter, it would refresh the bitmap I have programmed to move.

If run = True Then If PictureBox1.Top + PictureBox1.Width >= Me.ClientRectangle.Bottom And PictureBox1.Visible = True Then Timermain.Enabled = False MsgBox("Game Over- Region of space not protected!") End If
Me.Refresh()
moveasteroid() End If

I guess this code is considered too sloppy for it to be looped?

The following code I'm trying to loop? Once either the asteroid gets past the bottom of the form, and then the message box loads stating game over. Once the x is clicked or in my case tapped, the game starts all over again.

Dim rocketleft As Boolean
Dim rocketright As Boolean
Dim asteroidspeed As Integer
Dim asteroiddrop As Integer
Dim asteroiddown As Boolean
Dim rocketspeed As Integer = 24
Dim missilespeed As Integer = 24

Private Sub Timermain_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timermain.Tick
moveasteroid()
checkgameover()
moverocketship()
firemissile()
checkhit()
End Sub

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
loadsettings()
End Sub

Private Sub loadsettings()
asteroiddown = True
asteroidspeed = 3
asteroiddrop = 40
checkgameover()
rocketspeed = 18
missilespeed = 24
missile.Visible = False
firemissile()
checkhit()
End Sub

Private Sub moveasteroid()
'Asteroid 1
If asteroiddown = True Then
PictureBox1.Top += asteroidspeed
Else
PictureBox1.Left -= asteroidspeed
End If
If PictureBox1.Left + PictureBox1.Width > Me.ClientRectangle.Bottom Then
asteroiddown = False
PictureBox1.Top += asteroiddrop
End If
'Asteroid 2
If asteroiddown = True Then
PictureBox2.Top += asteroidspeed
Else
PictureBox2.Left -= asteroidspeed
End If
If PictureBox2.Left + PictureBox2.Width > Me.ClientRectangle.Bottom Then
asteroiddown = False
PictureBox2.Top += asteroiddrop
End If
'Asteroid 3
If asteroiddown = True Then
PictureBox3.Top += asteroidspeed
Else
PictureBox3.Left -= asteroidspeed
End If
If PictureBox3.Left + PictureBox3.Width > Me.ClientRectangle.Bottom Then
asteroiddown = False
PictureBox3.Top += asteroiddrop
End If
'Asteroid 4
If asteroiddown = True Then
PictureBox4.Top += asteroidspeed
Else
PictureBox4.Left -= asteroidspeed
End If
If PictureBox4.Left + PictureBox4.Width > Me.ClientRectangle.Bottom Then
asteroiddown = False
PictureBox4.Top += asteroiddrop
End If
'Asteroid 5
If asteroiddown = True Then
PictureBox5.Top += asteroidspeed
Else
PictureBox5.Left -= asteroidspeed
End If
If PictureBox5.Left + PictureBox5.Width > Me.ClientRectangle.Bottom Then
asteroiddown = False
PictureBox5.Top += asteroiddrop
End If
'Asteroid 6
If asteroiddown = True Then
PictureBox6.Top += asteroidspeed
Else
PictureBox6.Left -= asteroidspeed
End If
If PictureBox6.Left + PictureBox6.Width > Me.ClientRectangle.Bottom Then
asteroiddown = False
PictureBox6.Top += asteroiddrop
End If
'Asteroid 7
If asteroiddown = True Then
PictureBox7.Top += asteroidspeed
Else
PictureBox7.Left -= asteroidspeed
End If
If PictureBox7.Left + PictureBox7.Width > Me.ClientRectangle.Bottom Then
asteroiddown = False
PictureBox7.Top += asteroiddrop
End If
'Asteroid 8
If asteroiddown = True Then
PictureBox8.Top += asteroidspeed
Else
PictureBox8.Left -= asteroidspeed
End If
End Sub

Private Sub firemissile()
If missile.Visible = True Then
missile.Top -= missilespeed
End If
If missile.Top + missile.Height < Me.ClientRectangle.Top Then
missile.Visible = False
End If
End Sub

Private Sub checkhit()
If (missile.Top + missile.Height >= PictureBox1.Top) And (missile.Top <= PictureBox1.Top + PictureBox1.Height) And (missile.Left + missile.Width >= PictureBox1.Left) And (missile.Left <= PictureBox1.Left + PictureBox1.Width) And missile.Visible = True Then
PictureBox1.Visible = False
missile.Visible = False
End If
If (missile.Top + missile.Height >= PictureBox2.Top) And (missile.Top <= PictureBox2.Top + PictureBox2.Height) And (missile.Left + missile.Width >= PictureBox2.Left) And (missile.Left <= PictureBox2.Left + PictureBox2.Width) And missile.Visible = True Then
PictureBox2.Visible = False
missile.Visible = False
End If
If (missile.Top + missile.Height >= PictureBox3.Top) And (missile.Top <= PictureBox3.Top + PictureBox3.Height) And (missile.Left + missile.Width >= PictureBox3.Left) And (missile.Left <= PictureBox3.Left + PictureBox3.Width) And missile.Visible = True Then
PictureBox3.Visible = False
missile.Visible = False
End If
If (missile.Top + missile.Height >= PictureBox4.Top) And (missile.Top <= PictureBox4.Top + PictureBox4.Height) And (missile.Left + missile.Width >= PictureBox4.Left) And (missile.Left <= PictureBox4.Left + PictureBox4.Width) And missile.Visible = True Then
PictureBox4.Visible = False
missile.Visible = False
End If
If (missile.Top + missile.Height >= PictureBox5.Top) And (missile.Top <= PictureBox5.Top + PictureBox5.Height) And (missile.Left + missile.Width >= PictureBox5.Left) And (missile.Left <= PictureBox5.Left + PictureBox5.Width) And missile.Visible = True Then
PictureBox5.Visible = False
missile.Visible = False
End If
If (missile.Top + missile.Height >= PictureBox6.Top) And (missile.Top <= PictureBox6.Top + PictureBox6.Height) And (missile.Left + missile.Width >= PictureBox6.Left) And (missile.Left <= PictureBox6.Left + PictureBox6.Width) And missile.Visible = True Then
PictureBox6.Visible = False
missile.Visible = False
End If
If (missile.Top + missile.Height >= PictureBox7.Top) And (missile.Top <= PictureBox7.Top + PictureBox7.Height) And (missile.Left + missile.Width >= PictureBox7.Left) And (missile.Left <= PictureBox7.Left + PictureBox7.Width) And missile.Visible = True Then
PictureBox7.Visible = False
missile.Visible = False
End If
If (missile.Top + missile.Height >= PictureBox8.Top) And (missile.Top <= PictureBox8.Top + PictureBox8.Height) And (missile.Left + missile.Width >= PictureBox8.Left) And (missile.Left <= PictureBox8.Left + PictureBox8.Width) And missile.Visible = True Then
PictureBox8.Visible = False
missile.Visible = False
MsgBox("Region of space protected!")
End If
End Sub
Private Sub checkgameover()
If PictureBox1.Top + PictureBox1.Width >= Me.ClientRectangle.Bottom And PictureBox1.Visible = True Then
Timermain.Enabled = False
MsgBox("Game Over- Region of space not protected!")
End If
If PictureBox2.Top + PictureBox2.Width >= Me.ClientRectangle.Bottom And PictureBox2.Visible = True Then
Timermain.Enabled = False
MsgBox("Game Over- Region of space not protected!")
End If
If PictureBox3.Top + PictureBox3.Width >= Me.ClientRectangle.Bottom And PictureBox3.Visible = True Then
Timermain.Enabled = False
MsgBox("Game Over- Region of space not protected!")
End If
If PictureBox4.Top + PictureBox4.Width >= Me.ClientRectangle.Bottom And PictureBox4.Visible = True Then
Timermain.Enabled = False
MsgBox("Game Over- Region of space not protected!")
End If
If PictureBox5.Top + PictureBox5.Width >= Me.ClientRectangle.Bottom And PictureBox5.Visible = True Then
Timermain.Enabled = False
MsgBox("Game Over- Region of space not protected!")
End If
If PictureBox6.Top + PictureBox6.Width >= Me.ClientRectangle.Bottom And PictureBox6.Visible = True Then
Timermain.Enabled = False
MsgBox("Game Over- Region of space not protected!")
End If
If PictureBox7.Top + PictureBox7.Width >= Me.ClientRectangle.Bottom And PictureBox7.Visible = True Then
Timermain.Enabled = False
MsgBox("Game Over- Region of space not protected!")
End If
If PictureBox8.Top + PictureBox8.Width >= Me.ClientRectangle.Bottom And PictureBox8.Visible = True Then
Timermain.Enabled = False
MsgBox("Game Over- Region of space not protected!")
End If
If PictureBox8.Top + PictureBox8.Width >= Me.ClientRectangle.Bottom And PictureBox8.Visible = True Then
Timermain.Enabled = False
MsgBox("Game Over- Region of space protected!")
End If
End Sub

Private Sub moverocketship()
If rocketleft = True And rocketship.Left + rocketship.Width > Me.ClientRectangle.Left Then
rocketship.Left -= rocketspeed
End If
If rocketright = True And rocketship.Left + rocketship.Width < Me.ClientRectangle.Width Then
rocketship.Left += rocketspeed
End If
End Sub

Private Sub Form1_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles MyBase.KeyDown
If (e.KeyCode = System.Windows.Forms.Keys.Left) Then
rocketleft = True
rocketright = False
End If
If (e.KeyCode = System.Windows.Forms.Keys.Right) Then
rocketright = True
rocketleft = False
End If
If (e.KeyCode = System.Windows.Forms.Keys.Up) And missile.Visible = False Then
missile.Top = rocketship.Top
missile.Left = rocketship.Left + (rocketship.Width / 2) - (missile.Width / 2)
missile.Visible = True
End If
If (e.KeyCode = System.Windows.Forms.Keys.Down) Then
Application.Exit()
End If
End Sub

Private Sub Form1_KeyUp(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles MyBase.KeyUp
If (e.KeyCode = System.Windows.Forms.Keys.Left) Then
rocketleft = False
End If
If (e.KeyCode = System.Windows.Forms.Keys.Right) Then
rocketright = False
End If
End Sub
End Class

VS 2003 is what I'm using, it isn't for the desktop. I am developing for a mobile device, for educational purposes.  Windows Mobile 2002.