After single-handedly launching the metal idol genre with a run of brilliant singles and a hyper-fun self-titled debut album, the Babymetal crew return with Metal Resistance, a second album that alters their winning formula in some important ways.

Band mastermind Kobametal and the writers and producers he hired have cut out some of the more playful elements of their sound in favor of a heavier, more serious approach.

Yes, the main concept of a trio of chirpy J-pop girls singing in unison over thrashing metal riffs and pummeling beats is still the basis of their genius, but this time there are no reggae interludes, no dubstep breakdowns, fewer bubblegummy melodies, almost no cookie-monster vocals, and no songs about chocolate and their desperate need to have it.

In their place are some nu metal influences that cause the songs to grind instead of soar, a mawkish piano-and-strings ballad ("No Rain, No Rainbow") that White Lion would think was soft, and a general lack of fun that is totally at odds with their first record.

Maybe spending so much time with serious metalheads, on-stage and at awards shows, led the brain trust behind the group to aim for something their new peer group wouldn't scoff at (too much).

The attempt at sounding like someone's idea of what real metal should be falls flat, with the epic-scaled "From Dusk Till Dawn" coming off pretentious and overstuffed, and too many songs relying on riffs that Linkin Park already wore out years before.

Luckily, there are still flashes of the project's original style that come through about half the time.

Tracks like "Awadama Fever," which has clattering breakbeats underneath the super-hooky melodies, the hard-hitting "GJ!," and a few others sound like vintage Babymetal, and the girls, especially Su-Metal, sound just as confident and note-perfect as before.

They're blameless for the dip in quality on Metal Resistance; their collaborators let them down.

Kobametal would have been better served by not trying to reach for artistic growth or serious acceptance; another couple of frivolous and fun albums would have been just fine.

As it stands, Metal Resistance is still worth hearing, if only for the half of the record that captures the insanely silly balancing act that their debut managed so well.