Tensions within the band and its management resulted in an album that is highly eclectic in terms of its musical aesthetics, to the point that it has been rejected by the band's core audience as not being a Helloween album at all. This position is based on the notion that Helloween (arguably) created but, more importantly, had perfected the power metal sound.
Having failed to live up to the standard of Keeper Of The Seven Keys Part 1 and Keeper Of The Seven Keys Part 2 after Pink Bubbles Go Ape in commercial (and somewhat artistic) terms, Chameleon abandoned almost all elements of the power metal sound that the band had been instrumental in creating, and can be seen as an attempt to garner success in wider musical avenues like synthesizers, horns, acoustic guitars, the children's chorus of the Orchester Johann Sebastian Bach, violin, church organ, country music, grunge and swing, with participation of musicians like Stefan Pintev and Axel Bergstedt. The atmosphere of the album is closer to progressive rock, with some pop elements. While some of these elements may have always been a part of Helloween's sound, they were not in the forefront of their sound and were not the elements most celebrated by the bands core heavy metal audience. The song "Giants" has more power metal elements than any other song on the album. Chameleon was the first and last time these diverse influences would make it to the front of the band's sound. In terms of production, this is arguably the most accomplished album of the Michael Kiske era, well produced with an epic sound full of different stylistic influences. The name "Chameleon" is derived from the style change from song to song (as a chameleon changes color).
The album was a failure both critically and commercially, and vocalist Michael Kiske and drummer Ingo Schwichtenberg were fired after the subsequent promotional tour. The band then recruited vocalist Andi Deris from Pink Cream 69 along with drummer Uli Kusch and continued in a direction more akin to their earlier works.