Hopefully I posted this in the right thread. 

Apologies if I haven't. I'm still fairly new here.  

I'm trying to build up a PAL 3DS collection, and almost have a complete list of games released up to this point. 
Variations have always intersted me, and I wanted to attempt to obtain those as well. 
I've tried looking up variants, but all I can really find are console variants. How many variants are there on the covers? 
The only one I know is the Mario & Sonic London 2012 one, with one release having a background of the stadium, and the other with just a blue background. 
[This is excluding NFR carts.] 
Thanks in advance.