Changing an existing answer is a tricky and even dangerous thing with regards to old questions. In the case of games, you can never assume everybody is using the latest and greatest version. I know people who still play MC 1.2 and 1.4
At the same time, new information exists and a new answer therefore exists. Where, then, do we put this?
Scenario 1: Original answer-er comes in and updates their answer, preferably using some chronological meter.
As of version 0.2
As of version 0.1
Sadly, not everybody on the site bother keeping track of old answers, and frankly who has the time? Especially when everybody else can do if for you.
Scenario 2: Somebody else updates answer with new information, likewise keeping older answer(s) in chronological order.
In this case, the top answer and accepted answer is still seen as such, and now has the correct/updated information. Good?
It seems the main reasoning behind this is a top answer should always be the only correct answer because it is the top answer. (or replace top with accepted, you get the same meaning).
Scenario 3: You make your own answer with the current information.
What happens next? The original top answer get downvoted over time and your answer, assuming it is the new correct answer and well written, becomes upvoted and the new top answer.
Naturally, this could take time, but I have seen it happen. On my older account where I was using the original SO almost since its start I have an answer that has something close 5k downvotes because it is no longer the correct answer and I was too lazy to update it (actually, I went to update it one day and notice that) It had originally received over 2k upvotes when I stopped noticing or caring. A new answer was given, and was now the top answer. My answer was also the accepted answer.
So the real question is what is the preferred method?
For me it really is a matter of context. If I can say that at least 98% of the players are using the updated version then the original answer is merely historical. If the game is still widely used then I would create a new answer because people would still be looking for a solution.
If the game is outdated but the answer was even more outdated then I would update the original accepted answer (or highest voted) because a new answer would be unlikely to get any attention.
In either case if the original answer-er returns they can do what they want with their answer. But if the game is still played and the original answer is updated, then I see no reason to post a new answer or even edit in an answer.