In my experience, no. At least, not compared to learning other languages as a second or other language.
Mandarin has no gender, no case, no articles, no inflection, no conjugation or tense, no voice or mood. The grammar is remarkably easy, especially for speakers of English or Romance languages, who will recognize the core subject-verb-object pattern, both in simple and compound sentences. It’s much easier to build basic sentence capability, and much harder to speak incorrectly than other languages.
Most nouns are compound words, which, upon learning the literal meanings based on the underlying characters, are learned and memorized much faster than most other languages that are not in your the language family of you mother tongue. For example, the word “volcano” is fire-mountain, the word for “glacier” is ice-mountain, the word for “skates” is ice-shoes, etc. Once you have a vocabulary of about 300 of these “builder” words (which admittedly can be tough to learn, since those base words are nothing like your mother tongue, unless you speak another Chinese dialect), new common vocabulary is easy to learn and very literal. Once you know 3,000 base words (or characters), you can build more than 95% of the linguistic corpus of words.
Reading is a trick, for sure. But even with the difficulty of learning three to five thousand characters, it too can be learned more easily by learning instead the component parts of a characters. You see, even Chinese characters have a system, and once you have learned the “radicals” that make up the characters, those, too, can actually be learned very quickly, particularly in an immersion environment.
Since learning Mandarin, I have either dabbled in or studied rigorously Russian, Portuguese, Spanish, Dutch, Czech, Cantonese, German, French, Italian, and Vietnamese, and I find Mandarin to be easier than any one of them. Your mileage may vary, but like with most things, the difficulty in learning a language is inversely proportional to your motivation to learn it!