Another method that would look sharper would be a pixel filter on the camera. There are some on the asset store for cheap or you could write your own relatively easily. Here's one I found. https://www.assetstore.unity3d.com/en/#!/content/85326. Not what I did mind you but it would make things easier for some.
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Here is a free one I found. https://www.assetstore.unity3d.com/en/#!/content/16314