This is a pet peeve of mine:

s = s & "Public Sub Init(ByRef hWnd As LongPtr _" & n

I hate large blocks of code with this type of concatenation. I prefer to add each line to a Dictionary and join it's keys. But sense the text being concatenated is quite large and prewritten, I will spend 5 minutes figuring out how to generate the code.

For this example I dumped to code into a module and wrote this function to parse the modules code and copy the result to the clipboard.

Sub PrepareCode()
    Dim Lines() As String
    With ThisWorkbook.VBProject.VBComponents("APICode").CodeModule
        Lines = Split(.Lines(1, .CountOfLines), vbNewLine)
    End With
    
    Dim n As Long
    For n = 0 To UBound(Lines)
        Lines(n) = "Lines(" & n & ") = " & Chr(34) & Replace(Lines(n), Chr(34), String(2, 34)) & Chr(34)
    Next
    
    With New DataObject
        .SetText Join(Lines, vbNewLine)
        .PutInClipboard
    End With
End Sub

APICode: Module

#If VBA7 Then
    Private Declare PtrSafe Function IsWindow Lib "user32" (ByVal hWnd As LongPtr) As Long
    Private Declare PtrSafe Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hWnd As LongPtr, ByVal wMsg As Long, ByVal wParam As LongPtr, ByVal lParam As LongPtr) As LongPtr
    Public Declare PtrSafe Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)
#Else
    Private Declare Function IsWindow Lib "user32" (ByVal hWnd As Long) As Long
    Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hWnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
    Public Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)
#End If

Output

Lines(0) = "Option Explicit"
Lines(1) = ""
Lines(2) = ""
Lines(3) = "#If VBA7 Then"
Lines(4) = "    Private Declare PtrSafe Function IsWindow Lib ""user32"" (ByVal hWnd As LongPtr) As Long"
Lines(5) = "    Private Declare PtrSafe Function SendMessage Lib ""user32"" Alias ""SendMessageA"" (ByVal hWnd As LongPtr, ByVal wMsg As Long, ByVal wParam As LongPtr, ByVal lParam As LongPtr) As LongPtr"
Lines(6) = "    Public Declare PtrSafe Sub Sleep Lib ""kernel32"" (ByVal dwMilliseconds As Long)"
Lines(7) = "#Else"
Lines(8) = "    Private Declare Function IsWindow Lib ""user32"" (ByVal hWnd As Long) As Long"
Lines(9) = "    Private Declare Function SendMessage Lib ""user32"" Alias ""SendMessageA"" (ByVal hWnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long"
Lines(10) = "    Public Declare Sub Sleep Lib ""kernel32"" (ByVal dwMilliseconds As Long)"
Lines(11) = "#End If"
Lines(12) = ""

I'm looking forward to testing this code out with a snake game I made awhile back!