"You should go back and retrieve it."
On February 20th 1995 Bungie released a Marathon v1.0==>v1.1 Updater. The v1.1 Updater contained a number of bug-fixes and enhancements for the release version of Marathon v1.0. The Updater's Release Notes documented these.
While Marathon v1.1 offered a number of improvements it caused a major problem with mouse control. Indeed the mouse control problems lead to a long and vitriolic thread on usenet entitled "Marathon 1.1 SUCKS!". Others bemoaned the lack of ARA support in the update. Through all the nashing and grinding of teeth at least one person had the good sense to post something funny.
The mouse control problem however was serious enough to make using the mouse with Marathon v1.1 almost impossible and the upgrade was perceived more as a downgrade for mousers. Faced with mounting complaints Bungie quickly set about addressing the mouse problem in version 1.2.
The v1.1 Updater also made a number of undocumented changes. Two are described below.
Firstly, a series of "nasty words" were mysteriously introduced into the data fork. Modesty prevents me from printing them here. For obvious reasons they didn't appear in Marathon v1.2.
Secondly, a terminal was changed. But which one?
Simon Brownlee <firstname.lastname@example.org> writes:
Seeing as noone else has come up with the answer, I'll give it a go.
The V1.1 update fixes the terminal tags for Habe Quiddam. HQ is a retrieval level where you are supposed to collect the alien power converter, which presumably allows you to interface with the alien control panels, save buffers and alien weapon (although the exact use is never really defined).
In version 1.0 the exit terminal uses a 'failure' tag to display a message that you haven't collected the the power converter yet. However, 'failure' tags are only activated for Rescue levels when you haven't saved enough BoB's, so on this level, you would _always_ get the success message whether or not the mission is complete - a major flaw in the story line.
Version 1.1/1.2 changes the 'failure' tag to an 'unfinished', thus ensuring that the mission is complete before teleporting off to Neither High nor Low.
Ah close... very close... unfortunately not close enough to win the SECRET first prize! ;-)
Simon is correct except for the fact that NO message was displayed at the final terminal if you arrived WITHOUT the alien energy convertor. This cause considerable problems for some people playing the release version. Failure to pick up the alien energy convertor meant that you could not get off the level BUT the final terminal never displayed its failure message:
***INCOMING MESSAGE FROM DURANDAL***
You didn't get the present that the S'pht so kindly left for
you. You should go back and retrieve it. I could let you
leave without it, but you'd be sorry later.
***END OF MESSAGE***
As no message was displayed (the terminal simply blinked on and off) there were no clues as to what the player had failed to do. This caused some people to wander around "Habe Quiddam" hopelessly trying to find another way off. Without the alien energy convertor there was NO way off. Of course Durandal did tell you to retrieve it at the very beginning but some people just didn't bother to take the time to read it.
The display of the failure message in Marathon v1.1 did correct this problem.