You are using Python 2.x.
In this version the tkinter module is called Tkinter (note the capital T). You can either download version 3.x, or rewrite in the files where you see tkinter to Tkinter.
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.
5 years ago(+1)
I solved it: When I installed Python I selected the option to only install py launcher and not IDLE. For some reason, tkinter is only bundled with the development environment.
I might post a comment about the game itself later.