Röyksopp deliver a poor, thoroughly underdeveloped, and, dare I say it, unfinished fourth effort.

Be careful what you wish for. It’s a phrase that so often becomes painfully relevant in pop music. Take Radiohead’s Kid A and Amnesiac records: those who didn’t “get” it were crying out for that long awaited OK Computer 2. What they got was Hail to the Thief, an uncomfortable return to rock that never quite finds its feet. I personally find that the Radiohead of the early noughties is the Radiohead that I enjoy the most. By the same token, after Röyksopp became progressively more and more pop-oriented with each record, I began to return increasingly to the thoughtful yet achingly fragile electronic burblings of the Swedish group’s gorgeous debut, Melody AM. As great as synthpop gems “The Girl and the Robot” and “Only This Moment” were, part of me wanted the band to return to their humble roots.

It seems that by wishing for this, I have jinxed it. First off, to its credit, it is worth stating that Senior is not a terrible record. There’s not enough going wrong to warrant that. But neither is it a great one. If there was ever a B-sides collection masquerading as a bona fide studio album, then this is it. With the kind of electronica showcased here, there’s a thin line between the mesmerising and the downright dull. “The Drug”, albeit sounding like computer game menu music, has a great enough synth hook to keep you in check with the beat for its duration, but “Forsaken Cowboy” and “The Fear” do way too little to justify their play time, all shuffling beats and loungey keys that were haunting on Melody AM, but soundtrack the sound of fingers drumming here.

It’s the sort of record that sounds beautiful if you dip into a track midway, but is tedious to listen to in its 55-minute entirety. (Older brother, 2009’s Junior, fits 2 more tracks into 5 less minutes.) It doesn’t help that Senior opens with its weakest tracks by far, “...And the Forest Began to Sing” and “Tricky Tricky” rehash “Tricky Two”, an uneventful and uncreative ten minutes of filler, which doesn’t bode well for the subtle and sparse 45 minutes to follow. Elsewhere, the opening 30 seconds of “The Fear” is eerily beautiful, but it soon delves into a cooking pot of dotted line synths and damp beats that has been taken off the boil. It’s all perfectly listenable, but middle-of-the-road just will not do for a band so melodically inventive band in the past.

Luckily, there are still a scattering of hints that not all is lost on planet Röyksopp. Besides the enjoyable, breathy deep house vibes of “The Drug”, “The Alcoholic” is the one other track that really recalls the glory days of Melody AM. Their unmistakably quirky chord sequences and alien blips and bloops are bittersweet, and seem to tell a story over the five minutes of “The Alcoholic”, something that the majority of the other tracks fail to do. Closer “A Long, Long Way” is also a begrudgingly gorgeous soundscape, despite Senior having done far from enough to justify such a vast, epic closing track.

Maybe it’s just its drastic contrast with the chirpy and pop-friendly Junior that makes Senior seem so dreary, but even out of context, Röyksopp’s latest seems like a poor, thoroughly underdeveloped and, dare I say it, unfinished effort. There are essentially about three original and diverting musical ideas here, and a couple of moving chord sequences. But to stretch out so few ideas over such a long period of time, for a band like Röyksopp, is not just disappointing, it’s worrying.

• Full album stream Soundcloud