o Paused mode (at least when --check-focus) while playing intro:
  even when window left the focus, the pause mode is set (would be
  pertinent to do this only if the window is no longer on top).
o On some machines, mouse click seems to be delayed (slow machine?
  -> try to change the FPS value,  SDL-related?).
o Sometimes (events queue badly resetted at startup?).
o SDL 2nd mouse button is in fact the 3rd one (wheel), with my
  IntelliEye/Xfree336 (im/ps2).
