Calling: an Unlogical Series of Events is a text-based homebrew game for the Nintendo DS handheld. Since it's text-based, the GUI here is very sparse. All you get is an on-screen keyboard on the touchscreen that you use to type.
A keyboard's all that's really needed here, really. All you have to do to progress is to type in various commands using the OSK and pressing Enter afterwards. You can check a list of available commands by typing "help".
Since it relies heavily on the touchscreen, Calling developer Chainsawkitten warns that you won't be able to type using an actual keyboard if you run the game on an emulator.
Download: Calling: an Unlogical Series of Events