Yes. Edits that add image descriptions (or in this case provides a transcript of text in an image) add accessibility without changing the core content of a post and should be accepted.
That said, this particular edit has been accepted, and it appears that the reject vote was a simple mistake.
Titles should be straight forward and in the form of a question. Your suggestion:
What game is this from? (probably an old Japanese arcade platformer)
There are two problems here. First, "probably" should not be in the title. What if it's wrong? So the whole phrase should go.
Even without the probably, this still isn't in the form of a question: ...
A proper image-less experience would show you the actual text of the buttons, as you can see by looking at the source of the page. For example the upvote button should show the "up vote" text as the source reveals:
title="This question shows research effort;
it is useful and clear (click again to undo)">