“Imaginaerum is Nightwish’s most eclectic and challenging work. That it suceeds is due largely not just to the talents of Tuomas, but the sterling work of Anette. In the hands of Tarja, an already over-the-top presentation might have been blown out of the water. Anette, sounding more than comfortably assured throughout, brings with her the requisite amount of light and shade to suggest she was the perfect fit.”

- Imaginaerum review, Metal Hammer

"This morning I woke up with a smiling grin on my face. This new music is so great that it has a positive physical effect on me, which hasn't really happened since Stargazers. It's like being a kid again and suddenly hearing Danny Elfman's Batman theme music or 'Duel of Fates' in Star Wars, for the first time in one's life. This is the degree of enlightenment. Bombastic happiness in music format. Almost as if all the previous album's were merely a pregnancy, and this is the actual birth... it was like holding a new-born baby. Tears were not far from it."

- nkorppi from NWofficial board

"Wait a second...is this really Nightwish? The otherwise sad and dark Nightwish?

Those samples sounded so playful and upbeat (well most of them anyway) that make me feel like I'm a child again in my world of fantasy. Nightwish is trying something new, and judging from these short samples, I think they're gonna do it. The quality of the samples is actually pretty good imo and those vocals...Anette has never sounded better."

- just some good man

"Imaginaerum definitely is the most challenging and maybe the most difficult album of Nightwish. When the repertoire will be stretched from the mix of a typical Finnish walz and musical box-lullaby through irish-folk-metal to a children choir and louge jazz during the first four tracks already, the listener can be assured that the album contents is exactly what the cover promises: roller-coasters and merry-go-rounds, amusement parks and ghost trains.

One has to sit in this Ferris Wheel for several rounds to believe that it even exist in the first place, and for the next, to figure out how far one can see from the top of it."

- Imaginaerum review by Mape Ollila, Imperiumi.net