If I enter "python --version" (in the same directory) it says " Python 3.7.4". Running a Search&Replace over all 3 files to change "tkinter" to "Tkinter" did not help either. Same error message, but now it complains about Tkinter not found with a capital T:
Viewing post in Minesimulator jam comments
Hmmmm...
The tkinter module is part of the standard Python library so it is extremely usual that you do not have it (neither tkinter nor Tkinter). You may have renamed the tkinter file. The only think I can think of then is to reinstall Python.
I'm sorry you weren't able to play the game without troubles. I'll make sure to pack my game into a directly executable file next time.