– Personally I dislike the spines (mainly the Gameboy logos) – would you care to share the sources so I can rearrange them for me or make some alternate ones?
By ditching the background for the logo, I tried to give the spine a cleaner look. Closer to the original game boxes.
I'm not sure about them myself, but I'm gonna stick with them for now. (Since I have already printed quite a few covers for my own games.)

I don't want to upload all my psd-files, since they are quite huge (some of them are over 100 MB).
But I could upload the psd for the spines. That schould be enough for you to rearrange them.

– Aspect ratio: If you use the wider sidebars from the forum template, you can keep the aspect ratio as or closer to the original.
I disagree with you on that part.

I did try to preserve the aspect ratio as good as possible and personally, I don't think the covers look as stretched out as many of the others do.
The sidebars from one of the templates are way to wide and I feel they ruin the look of the front cover.
– Speaking of the sidebar: Your advance logo has the “®” and the “™” with the latter being black instead of blue.
You are right about the “®”. I will remove this in future covers.
I'm not sure about the “™”. It does look pretty dark on the original boxes. But you are right. It might just be a very dark purple / blue color, instead of black. I will work on that.

– Oracle of Seasons: There is a typo in the english part (a hero foR all seasons). How did you fix the white part of the scan? Did you combine the NA and EU version?
What do you mean by "white parts"?
I happen to own the game (EU version). So the front cover is a scan of my own, edited with photoshop. (There are varios ways to improve "white parts".)
The backside of the cover is NOT a scan, but a complete reproduction.
The background I got from the manual of the game (manuals often have the same background as the box, but unobscured by logos or text.)
The text I typed in myself. (Sorry for the typo!^^)
– Four Swords: She is a pain to descreen but maybe she could use some more?
Yes, it was a pain and no, I don't think I can improve it much more.

At least not without reproducing the background.