I love the design. The pixellated edge, especially going through the heart when the acrylic pieces are together, give it a strainght-outta-Scott-Pilgrim aesthetic. Nice!

Thanks! The pixel design is befitting as this pendant is a piece of swag for MAGwest, which is the west coast version of MAGfest, the music and games festival, which is all about that asthetic in every possible way!
Originally, we were supposed to license a design from Jeremy Brown which was a heart with NES controller styling. But this hadn't happened by the time I was getting quotes for PCB manufacturing, and finally the folks in charge of that gave up. In order to not infringe IP, I had to come up with an original design that would still work with the (already debugged) board layouts that we had sent to China, as there was no time to build and debug another board and re-quote the project.
So I came up with the 8-bit pixel heart design in one night, and changed the NES buttons to tiny pixel hearts also. I changed only the soldermask and the board outline, sent the new files to China and started the manufacturing process. Because the copper layers hadn't changed, I wasn't worried that the changes to the design would cause it to fail, and it didn't!
Great!
Except that it had a large impact on the amount of laser cutter time needed to cut the project, which was charged at a (heavily discounted) $1 per minute. The jaggies not only make for a longer path than a smooth sweep, but also require a start and stop of the laser in each corner. I somewhat mitigated this by adding a fillet in each corner, but it was still a lot of time, and the acrylic cutting was going to cost more than the PCBs!
But once I got the boards back, I noticed that it was very hard to assemble my dual-pinheader connectors with all of the layers of jaggy acrylic; minor variations in the alignment of the soldered parts made them almost impossible to line up.
To solve this, I scalloped out jaggies on all but the outside edge and the outer layers of acrylic, leaving a smooth curve behind the pin-headers inside the heart. I also changed the inside of the button holes to be smooth edged instead of following the jaggies of the buttons, as it caused the buttons to jam (there were other reasons for this as well, but this was my first problem with those). This made putting the two heart halves back together easier, although not as trivial as I'd like. I tested it on three people and they could do it, so I decided it was good enough.
The design changes also had the side effect of drastically decreasing the cut time (and cost!) and saving the project from certain financial demise!
Now, i could tell some stories about the buttons and the many problems with those, or the problems of acrylic not being the thickness advertised, or the interesting way I handled my RFQ for the PCBs, but I should save some stories for actual project logs...
Everything was documented as I went on the Slack chat for MAGwest, but it all takes the form of conversations and status updates. I hope to eventually find time to crawl through it to make a nice set of log posts for this project, but I'm currently engaged in another project for a Hackaday Prize entry and don't quite have time for it.
I could just cut and paste the chat, but I don't think that would read very well., but at least it would get done... What do you think? 

I just bought one of these at MAGlabs and I think they're an awesome idea really well executed. Do you have the AVR code posted somewhere?