We really don't know enough about this case to provide an answer although I'm inclined to agree with everyone above.
First, were there no agreements at all? When you made the purchase, were there terms of purchase? If this was a game such as what you'd purchase at Steam, I'd find it hard to believe there are /were no agreements.
Second, what are your damages that you are claiming - a lost game save?
Third, let's assume you have a cause of action. What is the damage worth? It is probably not going to be worth more than the cost of the entire game.
How many have the same problem or is it possible that you were one of the few to be impacted? Let's assume you have a cause of action. These are the types of problems that are most likely either: resolved directly with a vendor (who may wish to avoid the negative publicity and dispute for a relatively small amount); in a complaint to a state attorney general; in a class action assuming many others are impacted and the game developer has deep enough pockets to make an action worthwhile.