Hmm, yeah, I'd think Icelandic is pretty hard too. It's a really old language, I am for instance reading a book written in the 12th century and understand it without any training. Our language is very flexible, adjectives have 48 forms, one of three genders, either singular or plural, and with or without a definite article and 4 cases. Every noun has 16 forms like for example hestur (horse) is declined like this
Our verbs are also conjugated by person, Ég hleyp (I run) žś hleypur (you run) Hann/hśn/žaš hleypur (he/she/it runs) Viš hlaupum (we run) žiš hlaupiš (you run) žeir/žęr/žau hlaupa (they run).
Spelling can be a bit confusing e.g. y-i, ż-ķ, ey-ei, all of these pairs sound the same and whether to use one or two n's.
And I could go on, but won't bore you :')