There's a reason Nintendo didn't show off the main console unit when the Wii U was revealed back in 2011. The GamePad would be what defined this console.
It is a tablet? Nope. The Wii U's main controller is more akin to the bottom half of a 3DS blown up to about five times the size.
At 10.2 inches wide, 5.3 inches tall and 0.9 inches deep, it's a chunky beast, but a deceivingly lightweight one. It feels a bit cumbersome when you first pick it up but spend some time with it and you'll appreciate the brilliance.
Despite its rectangular shape, the moldable grips and weight make the the 'Pad perfectly comfortable for long gaming sessions. Yeah, it's plasticky - certainly not up to the design standards of the likes of the Nexus 7 if you're still comparing it to an actual tablet - but it's been built with budget in mind.
And slap bang in the middle is a 6.2-inch resistive touch screen that's brights and vibrant, even though it only crams in a 854 x 480 resolution display. The screen only recognises a single input at a time but you can opt to use either a finger or the stylus that comes stored in the top of the pad, both of which are equally effective.
But the only thing that matters is that the games look good - and they do. The onboard speaker isn't quite as crisp but there's the option to plug in headphones if you wish.
But Nintendo isn't ditching the classic controls. You've still got dual analog sticks as well as face, shoulder and trigger buttons to play with. There's also an NFC sensor below the D-pad and even an infrared sensor on top, allowing you to use the GamePad as a basic TV remote control if you set it up to do so.
Having your hands so far apart is an odd thing to get used to after generations of compact controllers but it doesn't take very long to get used it. After all, each hand is essentially in the same place it's always been. They're just a tad more distanced.
So that's everything Nintendo's crammed into its new controller, but what will you be using the Wii U GamePad for? As well as being a touchscreen controller for gaming, the 'Pad can handily act as a mirror for whatever you're playing on the TV - even with the television switched off.
All the processing power is done in the console unit, so if someone in the family wants to watch a film and you're mid-way through tearing Bowser a new one you can just switch to the GamePad and continue as you were. In fact, so long as the game supports off-TV play, you can play a game from start to finish completely on the portable screen.
There's zero lag when using off-TV play but there is a tether, and it's a frustratingly short one - a limitation that's even more annoying when the PS Vita lets you take the portable anywhere around the house. 10 metres is the average distance that the GamePad can be taken from the main unit, though I found that any wall that got in the way would diminish that distance.
Another tether of sorts is the GamePad's disappointing battery life. Somewhere between three and four hours is the average time span on a single charge (though it's mostly closer to three), which isn't great. Luckily the charging cable is pretty long and you can squeeze out a bit of extra life from the controller by lowering the brightness, but we'd have hoped for more juice in there.
But the biggest problem with the Gamepad right now is that it simply still isn't being pushed to its attention. Donkey Kong Country: Tropical Freeze, which was released February 2014, completely shunned it. Seriously, a Nintendo first-party game released over a year after the console and the GamePad screen is blank the entire time.
And yet we've seen glimmers of just how brilliantly the GamePad can be used when developers approach it in the right way. Take ZombiU, where the Wii U GamePad transforms into your character's rucksack. - every time you need to rummage for an item you have to do so using the touchscreen, keeping one eye on the controller and the other on the TV screen for approaching brain-feeders. It really does foster a sense of panic.
Nintendo realises that the Gamepad is the console's unique feature and promises to utilise it more in the future, so fingers crossed it keeps to its word. Just off the top of my head I can think of a number of ways ways it could make multiplayer amazing. I reckon we all can.