3D Minecraft for TI Nspire CX calcs running Ndless
Thread on omnimaga: http://www.omnimaga.org/ti-nspire-projects/ngl-a-fast-(enough)-3d-engine-for-the-nspire/

Move around using the numpad: 8-4-6-2
Jump using 5
Switch the current inventory slot with 1-3
Open a list of blocks with "."
Set the current inventory slot with 5 while the block list is open
Put a block down with 7 and destroy a block with 9
Open the menu with menu, move the cursor with 8-2 and select it with 5
ESC is a shortcut for "Save & Exit"

crafti doesn't use floats, so there will be some graphical inaccuracies.