Brick Breaker 3D is an Arkanoid style wall breaker game by Technicmaster0. It's a bit simple at the moment and the author is looking for feedback to get the game improved. Read more about Brick Breaker 3D (RC 1) (3DS Game)
Labyrinth 3D is, as the title says, a game where you have to find the exit from the labyrinth you're in. It supports different map sizes and you'll have some scrolls according to map size. These scrolls can be used to "mark" a wall of the labyrinth so you can see where you already went (after marking a wall, it will become golden). Read more about Labyrinth 3D v1.2 (3DS Game)
OpenSyobon3DS aka Open Syobon Action aka CAT Mario has been ported to Nintendo 3DS by nop90. It's sort of a Mario game but with a devilish twist, it's really very difficult to play. Read more about OpenSyobon3DS v1.2 (3DS Game Port)
Atari800-3DS by asie is a port of the Atari800 8-bit home computer emulator to the Nintendo 3DS. Remember that this emulator requires Atari ROMs to be present in /3ds/atari800! Read more about Atari800-3DS v0.1.1 (A800 emu for 3DS)