Though now regarded as a classic, the early run of the show wasn't very successful, suffering poor ratings and an eventual production cut to 43 episodes. Producers were planning to pull the show once its run had finished but the ratings eventually began to pick up as the show got further along and became syndicated.
Because Sunrise was notoriously meager on resources at the time, production staffs could only work with 79 colors but were allowed to add another 3. This is in comparison to Uchû senkan Yamato (1974), who had over 300 colors including 82 different shades of gray to work with. This explains the animation quality the series have became retrospectively notorious for.
The reason that the episode "Kukurus Doan's Island" was cut from the English-Language version of Gundam was that it was cut at the request of Yoshiyuki Tomino himself. He felt that the episode's story was substandard, and it is doubtful that should a Japanese-Language DVD be completed, the episode would appear there either.
Tomino's original concept for the series was much darker, with Amuro dying halfway through the series, and the crew of the White Base having to ally with Char (who's given a red Gundam, no less), but finally having to battle him after he takes control of the Principality of Zeon. The original concept found expression in a series of novels written by Tomino soon after the show's conclusion, and elements of the storyline weaved themselves into Z Gundam and Gundam: Char's Counterattack.
Unusually for the time, the show was more geared for teens as opposed to children.