You can find this review in full at GBAtemp.net:
https://gbatemp.net/review/retroflag-handheld-controller-for-switch.2154/

Back when the Switch was originally announced, I had a vast assortment of miscellaneous excitements, each fuelled by the then-unique design. A dockable tablet with detachable controllers as a concept is phenomenal. You could have an entirely modular and upgradable platform between the dock, controllers, and tablet; the possibilities were endless for unique controllers, and docks that could provide power boosts when playing on the TV. In the end, my excitements remained just that. Nintendo never really iterated on the Joy Cons, and the dock is still just a block of plastic that’ll output HDMI and little more. My dreams of unique Joy Cons to match the company’s greatest controllers are all but up in smokes, at least officially speaking. While Nintendo sticks to its guns and holds tightly to its original designs, third parties continue to develop and iterate, and now we’ve finally arrived at my dream design with Retroflag’s very non-specific Handheld Controller for Switch. I’m in love.

Now there’s actually a good bit to break down here. On a surface level, we have a beautifully nostalgic translucent purple shell that’s designed to wrap around the Switch, interfacing with it via a USB C port at the bottom and being recognised as a wired Pro Controller. You have all the buttons you’d need for a Switch controller to work, with both sticks clicking in for a third input, and one additional button available for some nifty features we’ll go over later. Looking at the dimensions it’s 273mm wide and 110 tall, which is relatively comparable to Hori’s popular Split Pad Pro, if not a good bit sleeker in design. It’s got a really premium finish and holds both the standard and OLED Switch tablet well thanks to it overlapping the frame of the console on the left and right, as well as small clips on each side that catch the Joy Con rails.

To stop beating around the bush, what we have here is a controller grip that’s clearly inspired by the GameCube controller, and as I’ve commended Retroflag for in the past, they’ve done a brilliant job with the theming. Both analogue sticks feel great, and feature the growingly-popular magnetic hall effect sensors to avoid the drifting that’s plagued the vanilla Joy Cons. The D-Pad feels really nice, and definitely feels larger than the original GameCube controller’s. Each button feels great to press, with the plus and minus buttons, as well as the home, screenshot, and extra button being clicky; your usual face buttons by contrast have a satisfying travel distance to them. There have been some liberties taken to modernise the layout and bring it in line with what Switch games are expecting you to use, adopting the diamond-shaped ABXY over the GameCube controller’s own style. On top of this, we get a set of shoulder buttons and a set of digital triggers. I’m a little sad they didn’t jerry-rig something together to make the Switch think this is an actual GameCube controller so they could add analogue shoulder buttons, but I can imagine that’d add a number of restrictions that wouldn’t make sense given it’s only really Super Mario Sunshine that’d actually recognise them.

While I am on board with the modern take on the GameCube controller’s design, there are a few things I’m disappointed to see from this transition. Perhaps the most obvious of these for the eagle-eyed GameCube enthusiast is the lack of notches in the plastic surrounding each of the analogue sticks. It’s hard to really say whether this is a negative, since Switch games are probably expecting you to have full motion on both of your analogue sticks in oppose to being limited to an odd octagon. Even thinking like that though, I do think it’s a missed opportunity. Both analogue sticks just feel too close to the original, with this missing piece adding an initially-foreign sensation to the mix. Though an even more minor criticism than the lack of notches, the matte finish on the face buttons didn’t quite sit right with me at first, with the GameCube controller buttons being glossy. I will say that after using this controller for a week or so now, I’ve come on board to both of these discrepancies from the source material, and I do understand it can’t be exactly the same. With how close it is though, you’re overtly aware of anything that’s even slightly off.

I have been mentioning a special button, and it adds my favourite feature of third party controllers: rapid fire. If you hold the special button down and press any other button, the button will then have the hold mode rapid fire enabled. This means that if you hold the button down, it’ll act as though you’re mashing it. To give you an idea of how fast the mashing is, I decided to boot up Mario Party Superstars and start a game of Mecha Marathon. The aim here is to mash A and B as much as possible in 10 seconds. I managed to max out my score at 70m, so it seems plenty capable. On top of the hold mode, there is also a toggle mode that you can turn on by holding the special button and double tapping the button you want to enable it for. This will enable rapid fire regardless of whether you’re actually holding the button, and can be toggled on and off easily by just pressing the button.

The special button also has an additional feature in enabling you to remap buttons on the fly. The idea of this is a good one, but it is ultimately a useless feature for a reason I never expected: the controller is detected as an official Pro Controller by the Switch. What does this mean for button remapping? It means you can do it using the Switch OS itself, instead of having to rely on weird on-controller button combinations. On top of this, the controller even features motion control, though your use for this will likely be limited for handheld play. While the controller itself is perfectly comfortable, it doesn’t make for the best experience when playing a game like Splatoon 3 that expects you to be rotating the controller to aim efficiently. The one feature it’s missing versus an official Pro Controller is NFC support, but I don’t believe this is even possible to include with a wired controller, with even official Pro Controllers not allowing NFC usage with wired input enabled.

You do also get some rumble features here, with the controller vibrating to indicate when turbo functionality is turned on or off. It does also naturally work as you’d expect with Switch games. The one I looked at in particular was Splatoon 3, knowing it has a good variance in rumble strength between actions like swimming in ink and launching missiles. Though it can feel a little weak for the most subtle vibrations, it is noticeable and does enhance the larger experience. It has some of the subtlety you’d expect from HD rumble, even if it does fall slightly short on the strength.

Though the controller takes up the Switch’s USB C port, there is a USB C port on the bottom of the grip itself, allowing the Switch to be charged while you play. The only reason you’d need to take it out of the grip is if you wanted to dock it, since the additional bulk and slightly-repositioned USB C port would get in the way.

All in all Retroflag’s Handheld Controller for Switch is a hit with me. It looks great, feels great, and has all the features you’d realistically want from a Switch controller. With the only feature it’s missing being NFC support, I can highly recommend picking this up if you happen to see it in stock. At $70 you’re looking at a premium price, but I truly do believe this is a premium product to live up to that.