I can't raise your hopes because the game may have taken up the space. That said, go to the Play Store and download Root File Manager. It's a very small programme but it give you more clout than the built-in file manager. You don't need to root the tablet to use it.
When you get it running, scroll through the system folders and look for a folder named LOST.dir then open it. It's Android's equivalent to Windows Recycle Bin so with some luck, they may be there.