It supports 3DS and NDS games in a microsd card, for now, no need to download kernel for playing 3ds games, here are the steps I do to play 3ds/ds roms with the Stargate 3ds.
1 Format a microSD card with FAT32 on a PC.
2 Download the “DS menu system files” from the official site , unzip it, copy the contents to my sd card's root.
3 Also download some DS/3DS roms from -snip-, I get the game code from my seller, put .3ds/,nds files to the root of sd card too.
4 Plug the Stargate 3ds, it will show a 3ds game icon firstly. When I want to play ds games, press the 2 buttons on the card at a time, so the Stargate 3ds will enter into DS mode.