Next to game.exe should be file named log.txt. Open it and see which RenPy version your game use.
1. Make sure you don't use the walkthrough-mod. If you are not sure download the game again.
2. If the won't start, then try to launch it through RenPy SDK (
You must be registered to see the links
)
Note: You may need to adjust set the path to the folder where you store the game in Renpy's preferences settings. (The game needs to appear on the left panel when you start RenPy SDK)
3. If the game still won't start, then try to recompile it by clicking on "Build distributions".