There is lots of evidence to support that freeing Jim is no more than a game to Tom. The first piece of evidence is that Tom doesn't believe that freeing Jim is the right thing to do. Tom still thinks of slaves as less than him and he isn't friends with Jim the way that Huck is. Another piece of evidence that this is a game to Tom is the elaborate escape plan that Tom has made up. Tom goes over the top and does things that aren't even remotely necessary to free Jim. Finally Huck and Tom manage to free Jim from his shed, but then they lock him back inside the shed.