 The level of detail went so far, that the External Tank (ET) painted in white color was only displayed in the earliest available scenarios while the later one displayed the brown it wore later on.As the missions themselves were fairly complex, the game would optionally provide a high level of hand-holding.Instructions were passed to the player on a 'teleprinter', and when those instructions required the player to use the shuttle controls, the appropriate switch or knob would be indicated by a flashing box.