And Alt+F4 to quit.
Seems to work fine.
1) The mouse pointer is bound to the window boundaries, even after alt-tabbing. In other words, if I switch to another application or the desktop, I cannot move the mouse cursor somewhere else than the area used by the 3D HoL.
2) People with non-QWERTY keyboard layouts (AZERTY like me or DVORAK I suppose) won't be able to navigate correctly. Later you should let people have the possibility to redefine the keys or find another way to read the key input.