Hey, first time posting even though I've had my own personal cover project under way for the last two years now. It's a physical media wide initiative, spanning my movies, games, music, and applications -- so it's probably more OCD-ish than most lol. I'm trying my hardest (including building my own templates) to fit everything into poly CD/Mini DVD cases to save shelf space, and after some expensive trial and error (which included me just getting an Epson Artisan 837 Printer due to Staples being lames about printing out my covers), I finally got a system going that worked. Then I ran into retro gaming and saw an issue I've been trying to resolve for about six months.
Universal game cases, rightfully so, are ridiculously huge. It would completely throw off my uniformity due to the size difference height wise. I wanted to play these games again and reconnect with my childhood, but I didn't want the eye sore of different size cases on my shelf. This whole project started because just the size differential from DVD to Blu-ray was irking me to no end LOL. Luckily (or unluckily), I don't have about 30 SNES games sitting around loose to where I'd be forced to use those cases. My entire retro library got stolen about 10 years ago (was living in a horrible neighborhood) and the only loose carts around my apartment now are the 2-3 games my girlfriend has. Not a big deal there, but if I wanted to jump start my collection again, I'd have to make a decision about how to go about this.
Then I found out about flash carts for the NES, SNES, Genesis, and N64 and got an interesting idea. Instead of loading an entire game library onto one SD card, how about I just load the flash cart firmware + the single game ROM and put them into a DS Case? I know having an entire library in one place is the point, but I want each game to have a place on my shelf for reasons I'll get into later. Here's a mock up of Super Metroid by modifying a DS template to fit my needs:


I can fit an SD card and it's plastic shell case in there without modification if I just use gorilla glue to secure it.
I'm a bit crunched for space in the old style DS cases with the GBA slot, but gluing on the left side shouldn't be an issue if I had to. In the new eco cases from Nintendo I'm sure this is even easier thanks to the abundance of space. Speaking of which, I'm pretty sure you can do the same method with GBA carts in eco cases if you buy the GBA cartridge cases off eBay and super glue them in. I personally haven't tried this, but I will give it a whirl when I can (I was also going to try a similar trick with PSP games in CD Poly cases). I also found that the SD card shell will fit snuggly into the DS card slot if you slide it in to the bottom prongs. The upper half isn't secured, but if you close the case and move it around it's not going anywhere. Still, I'd rather glue the shell down and remove the SD card for play that way so I'm not trying to keep up with two pieces.

Personally, if I wasn't trying to play on a real system, I'd just use Compact Flash since I'd get more room on the label to design and print custom art, but all flash carts use SD these days and it's cheaper. Non SDHC 2GB cards are about $5 a pop, and while still costly when you're talking about 25 games per system, it still is cheaper than paying $450 for a copy of Earthbound or $85 for Mario RPG lol. Besides, I only have a handful of SNES games I really love, so I think I can complete this project for a reasonable amount of money.
Next question you're probably asking is "Why buy a 2GB card for a 4MB game?". Brilliant question! This way I can add MP3 soundtracks/OC Remixes, PDF manuals, retro commercials, artwork, strategy guides, ROM Hacks, and anything else related to the game along with it. Just doing a test for Donkey Kong Country (which I'm including the Competition Cartridge with), all of the above stuff totaled up to 1.5GB. I also have the flexibility to jump between emulation and the real console and keep the same game saves, so it's a pretty good set up IMO.

Here you can see the spine is in line with the rest of my design set up, just a bit thicker. DS cases are basically the same height as Poly Cases, so when shelved it will look pretty seamless and clean. I absolutely loathe spines that have the logo art on them since they are hard to read from a distance, so I keep my spines text only for the most part. Back covers follow the same thinking, too:

Quick game synopsis, game stats (which vary depending on the system... I need to update this specific template to cover Super Everdrive compatibility, though), and contents. Simple and to the point.
Just wanted to get some feedback or give you guys some ideas
