On one hand low quality images will affect the performance of your hub as people expect to see something top quality and hubpages tries to enforce that where they can.
On the other hand if you are taking screen shots / pictures of classic games which probably only had really low quality that is an entirely different issue for readers. If the quality is as good as it can be this is not an issue for readers. Just make sure your image is crystal clear and sharp. It can be a great image, even though its old and dated.
Take a look at this screen shot of an Old Zelda Game. Its pixelated and old but the image quality is great.
If the image is clear but representing something with poor quality you should be able to get away with it.