The two other levels are battle maps, Nadine. Just start a battle server in HH98 or CC99 to check them out. Otherwise, you could search for the files, their names begin with "xmbattle", if i remember correctly.

As for "holiday levels": there are tons and tons. Too many to list them. Just search a bit around in the download section. One thing that came to my mind immediately was that two years old Xmas Pack by Wille and Blade, though. You can find it here.