You can't play the game once you complete it as it's a design choice.
I had plans to redo the AI but never got the time to do it.
If you want to play again you would have to delete the saved data
1. Press Win + R Key
2. Enter regedit in the text box and click ok.
3. Open HKEY_CURRENT_USER.
4. Open Software
5. Find FreezeStudios
6. Open it and delete Silent House