Solutions implemented, plus I've done more work on the look of the game. But two problems exist in my current version:

1. self.scorevar doesn't increment, only decrements

2. I can't figure out how to reset the timer when the Start button is clicked. (What happens if Start and then Stop and then Start are clicked is that the timer updates every 500 ms, instead of every 1000.)

   from tkinter import Tk, Frame, Label, IntVar from tkinter.ttk import Button from functools import partial from random import randrange

   class Game:

   def __init__(self):
       self.window = Tk()
       self.window.title("Onager Ornery Clicker")
       self.createwidgets()
   
   def createframes(self):
       self.frame1 = Frame(self.window)
       self.frame2 = Frame(self.window)
       self.frame1.configure(bg='silver',
                             relief='raised', border='15')
       self.frame2.configure(bg='silver',
                             relief='raised', border='15')
       self.frame1.rowconfigure(6)
       self.frame1.columnconfigure(5)
       self.frame2.rowconfigure(15)
       self.frame2.columnconfigure(5)
       self.frame1.grid(row=0, column=0, rowspan=6,
                        columnspan=5)
       self.frame2.grid(row=6, column=0, rowspan=15,
                        columnspan=5)
   
   def createtitle(self):
       self.title = Label(self.frame1)
       self.title.configure(bg='silver', fg='SlateBlue4',
                            font='serif 30', justify='center',
                            padx='10', pady='10',
                            text='Onager Ornery Clicker')
       self.title.grid(row=0, column=0, rowspan=1,
                       columnspan=5)
   
   def createinstr(self):
       textstring="""Correct click scores a point.
   

   Incorrect click costs you a point. How quickly can you score points? Click Start to begin. HAVE FUN!!!""" self.instr = Label(self.frame1) self.instr.configure(bg='Silver', fg='SlateBlue4', font='serif 12', justify='center', text=textstring, pady='10') self.instr.grid(row=1, column=0, rowspan=5, columnspan=1)

   def createstart(self):
       self.start = Button(self.frame1)
       self.start['text'] = 'Start'
       self.start['command'] = partial(self.start_game)
       self.start.grid(row=1, column=2, rowspan=1,
                       columnspan=1)
   
   def createstop(self):
       self.stop = Button(self.frame1)
       self.stop['text'] = 'Stop.'
       self.stop['command'] = partial(self.stop_game)
       self.stop.grid(row=1, column=3, rowspan=1,
                      columnspan=1)
   
   def createscore(self):
       self.score_label = Label(self.frame1)
       self.score_label.configure(fg='black',
                                  font='serif 10')
       self.score_label['text'] = 'Score:'
       self.score_label.grid(row=3, column=2, rowspan=1,
                             columnspan=1)
       self.score = Label(self.frame1)
       self.score.configure(bg='black', fg='white',
                            font='serif 16')
       self.score.grid(row=5, column=2, rowspan=1,
                       columnspan=1)
   
   def createtime(self):
       self.time_label = Label(self.frame1)
       self.time_label.configure(fg='black',
                                 font='serif 10')
       self.time_label['text'] = 'Time:'
       self.time_label.grid(row=3, column=3, rowspan=1,
                            columnspan=1)
       self.time = Label(self.frame1)
       self.time.configure(bg='black', fg='white',
                           font='seriv 16')
       self.time.grid(row=5, column=3, rowspan=1,
                       columnspan=1)
   
   def createbuttons(self):
       index = randrange(0,74)
       for item in range(75):
           self.button = Button(self.frame2)
           if item == index:
               self.button['text'] = 'Click Me!'
           else:
               self.button['text'] = "Don't Click Me!"
           self.button['command'] = partial(self.clicked, self.button)
           rn, cn = divmod(item, 5)
           self.button.grid(row=rn, column=cn, rowspan=1,
                           columnspan=1)
   
   def createwidgets(self):
       self.createframes()
       self.createtitle()
       self.createinstr()
       self.createstart()
       self.createstop()
       self.createscore()
       self.createtime()
       self.createbuttons()
   

   class Play(Game):

   def __init__(self):
       Game.__init__(self)
       self.scorevar = IntVar()
       self.timevar = IntVar()
       self.initialize()
   
   def initialize(self):
       self.score['textvariable'] = str(self.scorevar)
       self.time['textvariable'] = str(self.timevar)
   
   def clicked(self, button):
       if self.button['text'] == 'Click Me!':
           self.scorevar.set(self.scorevar.get() + 1)
       else:
           self.scorevar.set(self.scorevar.get() - 1)
   
   def start_game(self):
       self.game_running = True
       self.update_time()
   
   def stop_game(self):
       self.game_running = False
   
   def update_time(self):
       if self.game_running:
           self.timevar.set(self.timevar.get() + 1)
           self.window.after(1000, self.update_time)
   

   def main(): onager = Play() onager.window.mainloop()

   if name=='main': main()