Hold on to your Diddy Kong Nintendo hats, folks. It's Retro Studios speculation time!

Early this morning, we shared with you a tweet from ex-Nintendo of America President, Reggie Fils-Aimé. The tweet gave us a look at some of his retirement gifts, which included a Virtual Boy, a lovely notebook, and a giant plastic bottom (yeah, seriously) but it also featured a gorgeous piece of artwork from Retro Studios.

You can see it for yourself in the image above - it features Donkey Kong, Diddy Kong and Dixie Kong, Samus and several Metroids, and something else conveniently obscured by a Mario statue. Now, most of these characters are from Nintendo games worked on by Retro Studios - you probably know that Retro developed games like Metroid Prime and Donkey Kong Country: Tropical Freeze - but what is this 'something else'?

A robotic-looking hand is clearly visible, although it doesn't look quite like anything we've seen in previous games, and if you look really closely underneath Samus' blaster, you can also see what appears to be some kind of robot mask. Perhaps it's someone wearing a VR visor? In all honesty, we've no idea what it is, but it certainly seems like it could be something that hasn't been announced just yet.

Excuse us while we get out our finest YouTuber red circles...
Excuse us while we get out our finest YouTuber red circles...

Things get even more interesting, though, when you realise the significance of the tweet below. Enrique Rivera is a concept artist at Retro Studios, and here he is, casually winking at the image being teased to the world. It's got to be something new, hasn't it?

Of course, we know that Retro Studios has now taken over the development of Metroid Prime 4, but we're likely not alone in thinking that the team must have been working on something else over the years, too.

Is this it? Let us know what you think in the comments below.

[via twitter.com, twitter.com, twitter.com]