I opted to skip on the Achievements for right now and am in the process of making this now. As all themes I've ever made, I'll give people the files and info if they care to make it a theme, but I manually create all my gamelist files and make all my own screen shots/start screens/sprite files, so unless you're going to take the time to do that, theme won't look good.
Here's a looping GIF of what it looks like so far. I've only grabbed 1/2 my SNES sprites so far and am using start screens for the screen shot until I get it fully set up and then I'll replace them with actual screen shots.
I think it came out pretty nicely, I may look into the Pegasus avenue, and need to really buckle down and improve any coding knowledge before I can even come close to my end goal.
PiTheme
Things that I plan on fixing is the GAME INFO box, and the Title Box. I'll have them expand to the size of the text inside, but I don't believe there is a way to pad the edges, so I don't know how I'll like the look.