Image copyright BBC/Channel 4 Image caption Clockwise from top left: Jodie Whittaker as The Doctor, Idris Elba in Luther and The Inbetweeners

Telly viewers were treated to a bumper crop of post-Christmas comebacks on New Year's Day - but some of them left the critics with the January blues.

There was praise for Doctor Who, whose seasonal episode "whizzed along at a cracking pace" according to one pundit.

The critics also welcomed Idris Elba's return as tough cop Luther, though one queried the show's "demonic" violence.

But there was little festive cheer for The Inbetweeners' Fwends Reunited 10th anniversary show over on Channel 4.

The "shambolic" programme, wrote The Telegraph's Michael Hogan, "failed to do [the original] justice" with its mix of clips, interviews and nostalgic reminiscences.

Warning: possible plot spoilers follow

In Doctor Who, Jodie Whittaker's Time Lord came face to face with a reanimated Dalek that, according to The Times, "looked a bit Dusty Bin".

The Mail's Christopher Stevens, though, was glad to see the Doctor's old adversary return, saying "it takes a Dalek to get things moving".

Image caption The Resolution episode saw part of a Dalek unearthed beneath Sheffield

The episode, he wrote, "built to a well-constructed climax" that made up for what had hitherto been "a slow, maudlin affair".

The result, opined The Independent's Ed Power, was "an enjoyably pulpy reprisal of Who's Greatest Hits" with "some zippy shoot-outs and much zinging around the universe".

Viewers were also delighted to see the Daleks - well, one anyway - make their first appearance on Doctor Who since Whittaker took over the Tardis.

"It's so good to have the Daleks back," wrote one fan on Twitter, while another called the show "a perfect capper for an imperfect yet intriguing series."

Yet disquiet was expressed about a scene in which the Doctor attempts to call the Unified Intelligence Taskforce - aka Unit - only to learn its operations have been "put on hold".

According to the Daily Express, viewers were left "fuming" by the implication that Brexit was to blame for the "financial disputes" behind Unit's disbandment.

Doctor Who drew an average audience of 5.15 million on BBC One on New Year's Day, according to overnight figures.

That may rise once the number of people who watch the show on devices as well as TVs is taken into account.

Whittaker's first full episode of Doctor Who attracted a consolidated audience of 10.9 million viewers when it aired in October.

Image caption Who's that girl? Ruth Wilson as Luther's murderous sidekick Alice

The first instalment in the latest series of Luther fared better in the overnights, attracting an average audience of 5.63 million.

Yet the critics were generally less positive about the show, which saw Idris Elba's detective on the trail of a serial killer stalking the streets of London.

According to The Independent's Ed Cumming (are all their critics named Ed? - Ed.), what "was gritty and fresh in 2010" now "feels flogged out".

The Mail's man said the show was "so graphic it will deter many viewers", while the Telegraph's suggested it "veered dangerously close to torture porn".

Yet the latter critic still considered the episode "a breathless opener" and praised "the wonderful Wunmi Mosaku" as Elba's new partner.

One scene in which a masked assailant creeps up on an unsuspecting young woman riding on the top deck of a night bus made a particular impression on viewers.

"That's me never ever getting on a bus again," tweeted actress Brooke Kinsella, while another Twitter user said it had given her "bus phobia for life".

The return of Ruth Wilson as the psychopathic Alice Morgan in the final moments of Tuesday's episode left viewers in a happier mood.

"I LOVE Luther... but I think I might just love Alice more," wrote one fan on Twitter, while another said her unexpected return was "the hottest thing I've seen on TV for years".

Image copyright Getty Images Image caption Joe Thomas, Simon Bird, James Buckley and Blake Harrison at the 2014 premiere of The Inbetweeners 2

There were few such raves for The Inbetweeners: Fwends Reunited, which Twitter users were quick to brand "painfully bad", "overhyped" and "a disappointment".

"Was anyone else under the impression The Inbetweeners special was going to be a two hour feature long episode, and not a talk show?" wrote another.

"This 10th anniversary celebration of the cult comedy... was awkward [and] overlong," rued the Telegraph's critic.

"It's just a shame Channel 4 tried to squeeze two hours of New Year's Day schedule-filler from such featherlight fare."

The Guardian's Pete Paphides said the show's four stars - Simon Bird, James Buckley, Blake Harrison and Joe Thomas - "looked really happy to be back together at the beginning but were already shifting uncomfortably after about 20 minutes."

"After 45, they looked like they'd fully checked out, which was pretty much the point at which I couldn't bear to watch any more," he wrote on Twitter.

An average audience of just over two million viewers turned in to see the two-hour programme, the first hour of which went head to head with Luther on BBC One.

Yet Channel 4 saw something to celebrate in those figures, saying it had been a hit with viewers aged between 16 and 34.

Luther continues every night this week on BBC One, while Doctor Who will return in 2020.

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