Current-gen is now last-gen. We'd love to move on, but we can't help wonder whether we've still got some unfinished business, a nagging feeling at the back of our minds.

In fact, thinking about it, there are a number of things that we were promised years ago, yet still haven't materialised despite the arrival of the Xbox One and PS4. Some are games that fizzled out of existence or sublimated into vapourware, others are features that were never implemented, many have been cancelled outright and more are just heartbreaking teases that dangled painfully out of reach... where they'll likely stay for months and years to come.

So here are a few things that went missing in action last generation. Let's kick things off with an old chestnut...

Agent

A first-person stealth game set during the cold war? Developed by Rockstar? Announced in 2007 and unveiled at Sony's E3 2009 press conference, Agent sounded too good to be true.

And it was. As the years slipped by, Agent continually popped up in trademark renewals and CVs, but is still far too stealthy for its own good. Will we see it on PS4? Perhaps, but don't hold your breath because you might end up asphyxiating.

Prey 2

Prey 2 utterly smashed it at E3 2011. A sequel we'd never expected suddenly became one of the most impressive games of show, promising a massive freeform bounty hunting playground that would have made Boba Fett blush under his Mandalorian helmet. We were so ready.

And then it... went away, due in part to issues within Bethesda and Human Head. We cried and wailed. Garments were rent in twain. Then we got on with our lives.

The last we heard from the rumour mill, Arkane Studios might be working on Prey 2 now, though are apparently a bit miffed at having to finish off someone else's IP. Grab that salt by the handful.

Spartan Ops: Season 2

Though some players hated Halo 4's cooperative extra campaign, we absolutely loved it. Indeed, every week we held SpOps Night to play through the latest episode, enjoying some crazy combat scenarios and Matt's continual attempts to "accidentally" run us over.

Then 343 Industries fell silent, before finally officially canning Spartan Ops' second season a few months later despite opening numerous new story threads.

More Rainbow Six

Rainbow Six: Vegas was an absolute peach. Ubisoft's shooter turned up to Generation Seven early and utterly smashed our expectations with its Persistent Elite Creation system, amazing cover system and the fact that we could stroll down a wall and shoot terrorists in the head while inverted. The sequel was fairly competent, but after going back to Calypso Casino for a few more months, we patiently waited for a true successor.

That never came. Rainbow Six: Patriots eventually broke cover due to a number of leaks and eventual official target footage, but as the years rolled on, another entry in the classic franchise simply failed to show up. Year after year we watched and attended Ubisoft's press conferences, expecting it to breach and clear, in vain.

To be honest, though, this might be for the best. Patriots' target footage and official announcements seemed to suggest a more story-driven and linear route for the series, which is absolutely not what we want from a Rainbow Six title. Fingers crossed for a storming next-gen return to form.

Final Fantasy VII HD

Square Enix never explicitly promised us Final Fantasy VII HD, in all fairness. Their top brass ruled it out until they've managed to create a new game that rivals the legendary JRPG, which is annoying, but noble in its own way.

But you didn't have to troll the entire fanbase by showing off the PS3 with a Final Fantasy VII tech demo, did you Sony? There's tactless, then there's just plain cruel.

All Those Ridiculous Kinect Promises

Kinect broke so many hearts over the last few years... mainly because it made so many ridiculous promises during the original Project Natal reveal. According to Microsoft, we were supposed to be able to scan objects and even our faces directly into our games. We could interact with lifelike AI who'd learn and grow, like poor old Milo. Natal could recognise our faces and voices, turn our living room into Minority Report and -- here's the best part -- actually let us play decent games.

None of which actually happened. The end result was a couple of reasonable minigame collections, Child Of Eden (which rocked), some deeply average games, a whole mess of compromises and the sinful horror of Steel Battallion: Heavy Armour.

Kinect 2.0 may be a voice control beast on Xbox One, but many gamers simply aren't willing to trust it. One bitten, twice shy. You can hardly blame them.

Half-Life 2: Episode 3

Don't even bother, Jon. You'll just end up depressing everyone. - Ed

Half-Life 3

Stop it. - Ed

Duke Nukem Forever

Now you're just being silly. - Ed

European TVii

We're not allowed nice things here in Europe. Case in point: TVii, the Wii U entertainment suite that brings fun new social features and controls to regular telly. The Americans got it. We didn't - and there's still no sign of TVii arriving on British shores.

Here's hoping that Microsoft are much more timely in bringing us OneGuide on Xbox One.

Tali's Face

We still haven't forgiven BioWare for this.

Dirty Harry

We love Harry Callahan (and all things Clint) here at Dealspwn, so the news of a Dirty Harry tie-in for Xbox 360 and PS3 was both joyous and sphincter-clenchingly worrying considering the state of most film adaptations. However, The Collective's effort was intended to be a standalone story set between Dirty Harry and Magnum Force, which in turn promised to bring more depth to the character along with "adaptive AI."

Sadly, it then got all but canned, despite the Facebook group still stalwartly posting.

The Too Human Trilogy (Or A Single Decent/Legal Game From Silicon Knights)

Too Human made huge promises and delivered on so few. It wasn't anywhere near as bad as many of my peers make out, at least in my personal opinion, but the potential for an epic Sci-Fi norse mythology trilogy ended up falling under the axe.

But we didn't really mind, because we still expected great things from Silicon Knights. They made Eternal Darkness, after all. Ooh, hey, an original ARPG based on the X-Men license! That could be a perfect way for them to return to active duty...

We all know the rest. Silicon Knights totally botched X-Men Destiny, shamelessly stole code from Epic Games, were destroyed in court and even ultimately failed to regroup with Shadow Of The Eternals. That last point is a bit of a shame, but in our opinion, Dyack's poor decisions and awful reputation has ultimately sullied the studio beyond saving.

Beyond Good & Evil 2

Oh Ubisoft, you certainly know how to raise our hopes and dash them expertly. We know that Michel Ancel has already put a huge amount of work into Beyond Good & Evil 2, he's ready to go, but why do you insist on teasing us with something we so desperately want before snatching it away again...

...wait, hang on. It's in active development and coming to next-gen consoles? Okay then. Hopefully Beyond Good & Evil 2 won't be MIA for much longer.

The Last Guardian

You didn't actually think that we'd forgotten about The Last Guardian, did you? Not a chance, in fact, we were saving the best for last.

I personally know people who bought a PS3, at least in part, because they wanted to play the next project from Team ICO - having been thoroughly entranced by ICO and Shadow Of The Colossus. The potential for greatness is clear, a tragic story of a young boy and his mythical creature (who will almost certainly die at the end but leave an egg or baby to continue its legacy, I'm calling it now) in a moody fantasy setting, providing all manner of opportunities for innovative gameplay and interactive storytelling.

"Tragic story" is the operative phrase here, because as you all know, The Last Guardian never turned up. Team ICO failed to deliver anything over the last seven years, while the legendary Fumito Ueda is now a freelance contractor on his own game. I've lost count of the number of times The Last Guardian was tipped for a re-reveal and rumoured to appear at trade shows, yet nothing came of it whatsoever.

At least this story might have a happy ending. The Last Guardian is still waiting for the right time to release... and more importantly, the right platform. With luck, the PS4 will finally let this eternally-delayed project see the light of day.