C:/Users/YOURUSER/Appdata/Local/Game Dev Tycoon/Local Storage/ where
YOURUSER is your Windows user name.
On Mac: ~/Library/Application Support/{app}/Local Storage
On Linux ~/.config/Game Dev Tycoon (might be slightly different)
On Windows 8 Store Version
C:\Users{User}\AppData\Local\Packages\B3B9BB81.56264F78B4FFF_swksbykwsp6kr\RoamingState
Where {User} is your username. If you could send us the file
corresponding to the save slot you use, that would help us a lot. So
slot 1 would be file 1 for example.