From the introduction:
Role-playing in the World of Hans Christian Andersen
"Ugly Ducklings and Ice Queens!" details the region to the north of the Magic Forest (the setting for NL01 "Fairies!"). GMs and players will have no difficulty importing characters from that setting, although fairies may find the climate in Hansland too inhospitable.
[W]e should mention here that some minor corrections have been made in the NUELOW rules, notably how encumbrance works, and the penalty/bonus values for skill levels. These changes are minor, however, and should not affect play too much.
Originally published as text in 1994; shortly thereafter published as HTML with edits; published in 2008 as PDF (possibly by a third party).