Sichuan is puzzle game that uses mah-jong tiles. The aim of the game is to clear the tiles by matching up pairs. NDS Sichuan has a Wi-Fi leader board where you can download the top 10 best times and compete against them in a challenge mode. If you manage to get in the top 10 you can upload your data over a Wi-Fi connection for others to download and challenge.
A save file gets created on the root of your card called nds_shisensho.nv. If having this file on the root irritates you then it's fine to move it to a different folder. I'm pretty sure it searches all directories for the file.
The latest version posted on MeRAMAN's blog was from the 29th of May and he fixed a couple of small bugs in the WiFi code. Oh... if you find that pixel font familiar, the one that's used in the "programmed by" text, yeah, it originates from Gradius 2.