HTC had a fancy trick up its sleeve when it launched the One (M8) – a special case mode that converted the display into a cool and retro 8-bit mode to give you time, weather and notification information. This wasn't available when I first reviewed the handset, but now I've had the chance to spend a decent chunk of time with it.

It's the same as Samsung's S View case in that it's an official accessory that adds something to the functionality of the phone by its mere presence, but doesn't just offer a tiny window into the phone.

This is a much more impressive option, as despite being clad in rubber and silicone, the front cover is still able to register touch for a variety of actions.

HTC One M8 review

The front cover of the case is packed with hundreds of tiny holes, but only those in front of the Boomsound speakers are uncovered to make sure sound can penetrate without distortion, but the rest have a clear covering to protect the screen as you'd expect a full case to do.

The main reason to being able to register touch is the double tap to wake the device, making it easy to check the time and see the weather, which alternates between an icon to let you know whether it's sunny or raining, and the temperature in a little animation.

If you get a message, the icon below changes to an 8-bit version of HTC's message notification, and the same happens if you swipe down from the top of the cover to automatically enable voice dialling.

If you've got a call coming in you can swipe up to take it or down to reject, with the latter motion still used when you're on a call – plus you can just hold the One (M8) to your ear to take the call if you've enabled that feature too.

HTC One M8 review

Annoyingly when a call comes in you can't always see the full name of the person who wants to get hold of you, with the name truncating rather badly – but then again, you can just open the cover to find out more.

The rest of the case is well put together and feels like it really protects the new HTC One, which is what you'd hope for when you're shelling out £35/$50/AU$50, which is pretty pricey.

However, there's a bigger problem with the cover, in that it doesn't fold all the way around unless you really force it. This leads to a hefty space behind the device when typing and holding it in one hand, and leaves an ugly angle when placing the phone down with the case open.

HTC One M8 review

And you can't even use this mode to watch a movie, with the stand not being able to prop up the phone on the hinge or anything, unlike the main case of the original One.

While I'm glad the flap closes properly thanks to the strong magnets on the front, this inability to fold should put off any prospective buyer, at least until HTC fixes the issue.

It's terribly frustrating as the 8-bit effect is awesome – you can get a sneaky peek at how it shows on the screen when you open the case for a microsecond.

HTC One M8 review

Most people I've shown the case to have been in awe of the clever little mode, which is good considering it's just a little trick with a couple of magnets and a team of designers putting in a few hours.

However, until the problem with the back folding away is sorted (the same thing means it's nigh-on impossible to take a photo with the case on, thanks to the front flap getting in the way no matter which way you hold it) I can't recommend this case to anyone, no matter how enamoured with the retro effect I am.