Code:
Option Explicit

Dim StartTime As Long, Mincount As Integer
Dim Minutes As String, Seconds As String
Dim TimeA As Long, TimeB As Long
Dim GameLength As Integer ' Playing Time in Seconds

Private Sub timeClock_Timer()
'    Dim lTemp As Long
'    Dim lTemp2 As Long
'    intCounter = intCounter - 1000
'    lTemp = intCounter
'    lTemp = lTemp / 1000 'convert to seconds
'    lTemp2 = lTemp
'    lTemp = (lTemp / 60) Mod 60 'Minutes
'    lTemp2 = (lTemp2 Mod 60) 'Seconds
'    If lTemp2 < 10 Then
'        lblTime.Caption = lTemp & ":0" & lTemp2
'    Else
'        lblTime.Caption = lTemp & ":" & lTemp2
'    End If
'    If intCounter = 0 Then
'        timeClock.Enabled = False
'        MsgBox "Times up"
'    End If

If (Timer - StartTime) / (Mincount + 1) > 60 Then Mincount = Mincount + 1
Seconds = Format$(60 * (Mincount + 1) - (Timer - StartTime), "00")
If Seconds = "60" Then Seconds = "00"
If GameLength - (Timer - StartTime) > 60 Then
    Minutes = Format$((GameLength - (Timer - StartTime)) \ 60, "00:")
    lblTime.Caption = Replace(Minutes & Seconds, "01:", "1:")
ElseIf GameLength - (Timer - StartTime) > 0 Then
   lblTime.Caption = Replace(Format$(60 * (Mincount + 1) - (Timer - StartTime), "00:00.0"), "00:", "")
Else: 'MsgBox "Game Over!"
End If
End Sub

Private Sub cmdClock_Click()
    If lblTime.Caption = "0:00" Then
        'intCounter = 150000 '20 minutes
    End If
    If cmdClock.Caption = "Start Clock" Then
        timeClock.Interval = 500
        TimeA = Timer
        StartTime = StartTime - Timer
        StartTime = StartTime + (TimeA - TimeB)
'        timeClock.Enabled = False
'        cmdClock.Caption = "Start Clock"
'    Else
'        timeClock.Enabled = True
        cmdClock.Caption = "Stop Clock"
        TimeB = Timer
    Else
        timeClock.Enabled = False
    End If
End Sub

Private Sub Form_Load()

    cmdClock.Caption = "Start Clock"
    GameLength = 120
    StartTime = Timer
End Sub