Acclaim was the only manufacturer to produce plastic clamshell cases for 32X games, and the only one (as far as I know) to print color instruction manuals. Meanwhile, everyone else (including Sega) used cardboard cases and black & white manuals (although Acclaim's Mortal Kombat II port was released in a cardboard case with a color manual).
Acclaim was a major third party player in the mid 90's; maybe they really felt that their 32X products needed to be higher quality than the competition.