GAMEMT teased a lot of ambitious handhelds earlier this year, and still, we're waiting for them to come to fruition. They teased one called the E5 MODX that had a modular display in April, which looked pretty cool, but very little else has been announced, making me believe it's still deep in development. Though we're now seeing one of their announcements in the wild, the MTX, a handheld that takes cartridges and also emulates some of your games.
It's a unique hybrid that I believe we'll see more of over the next year or two. We have already seen a mini handheld in the form of a GAME BOY be announced by FunnyPlaying a week ago that does the same, but it has a far more minimal, portable form factor and a much smaller screen.
So, what is this device? Well, there's no official information or announcement of this device's specifications as of now; the only information we have is the ones these small retailers and YouTubers are sharing, but a Chinese reseller known as Royibella has showcased this device on their YouTube channel, and it's apparently going on sale "this month" according to YouTube Nittrx, who has an early sample unit that he's been showing off on his YouTube channel, though oddly, we can't embed the video because embedding has been turned off on his side.
From what NITTRX states, this features a 720 x 720 display and AllWinner T509 CPU, 3.5mm headphone jack, HDMI out, GBA cartridge support, a full front glass panel, Linux OS, and WiFi.

It has the ability to emulate retro games up to and including PlayStation 1, though it has emulators for PSP too, but that would look darn uncomfortable on a 1:1 display like this. It seems odd to feature this screen type on a device that can play GBA cartridges. It will feature borders in almost all of your retro games, which is certainly going to dampen the experience slightly when you're not playing GAME BOY or NEOGEO games, for example.
In my opinion, it's not a bad-looking device, and GAMEMT are becoming more notable in the retro emulation space even if their build quality isn't up to scratch with competitors such as ANBERNIC, for example, but I like that they're willing to take risks; it's almost mandatory to do so in a market that has a new device releasing every single week. We'll update you with more information when we hear it, but it's likely this device will go on sale on AliExpress and other handheld retailers this month.