GDW's lack of understanding of 'shelf-appeal' for the product-line. Cover art is a
must to grab consumers' attention, and more interior art would have excited the imagination and set the tone of the game more readily. My Cr0.02.
Robot-design rules. For these I import concepts/mechanics from WEG Star Wars.
Ship-design rules. More design possibilities would have been very welcome. I also import from WEG SW.
Fondness for long, geeky hex stats for planets, ships, robots, etc. Enough already. :eyeroll:
An overbearing official campaign universe to which (mostly grognardy) gamers demand absolute, unwavering adherence. Violators will be punished. You will be assimilated. Resistance is futile. This has the very unsavoury effect of stiffling creativity essential for a homebrewed campaign.
Too many formulae which try hard to give the game a veneer of plausibility, but even slack-jawed, non-physicists (myself included) know full well they are not even remotely accurate for the portrayal of RL phenomena.
Emphasis in chargen on martial careers. The genre is very broad and the game needed to address other kinds of life-paths. Supplements, though belated, did partially address this shortcoming. [SWN is brilliant in that it offers more character background and training possibilities.]