A port of the MegaZeux game creation system to the 3DS. Note that the port only includes the player component and not the editor itself.

MegaZeux has a lot of great games available under the link above - I recommend the "Gold Collection".
Installation Notes

Use the R button to switch between "overview" and "keyboard" mode. The small "preview" on the touch screen can be used as a mouse.
Use the 3D slider to control the top screen's zoom level. On the 2DS, a special button should be available in the top-right of the keyboard mode instead.

Changelog
0.1.5

Major optimizations to rendering code