From what I can tell you about this port from the Lemmings port book I have, there is definitely no EU version. Only US and Jap versions exist.
The game contains 170 (50 missing) levels from Lemmings and Oh No More Lemmings and has 9 difficulty ranks. Fun, Tricky, Taxing, Mayhem, Tame, Crazy, Wild, Wicked and Havoc.
Max Lemmings 14
Despite coming out in 2000, 7 years after the game boy original version, it's mentioned that the game boy color version is just as bad because despite the added color, the music is terrible apparently.