This controller is an improved version of the 8bitdo Zero 2. Essentially, it is a miniature version of their Lite controllers and is the most portable option you can find with a slot to hang it even on your keychain. The buttons feel surprisingly good with satisfactory travel and clicky feedback, pleasantly surprising me. It is made of nice matte plastic that looks much more quality and sturdy compared to the glossy Zero 2, which seemed somewhat cheap and had minor creaks. Additional upgrades include now having four buttons on the "back" instead of two on the Zero 2, and the USB port is Type C instead of Micro USB. It connects instantly via bluetooth to anything you want, from android to PC. Its battery life is 7-8 hours, excellent for its size. It is also positive that a nice strap in the same color as the controller is included in the packaging.
The expected major issue is the uncomfortable grip. Its shape is more squared compared to the Zero 2, which slightly helps but still makes it difficult to hold between your fingers and obviously is not for serious gaming. In other words, for something to be portable, it doesn't need to be so comically small. The 8bitdo Lite 1 and 2 are the perfect balance between functionality and size, and even though they don't fit on a keychain, they fit in any pocket.
It definitely worth more than the Zero 2, but still the 20+ euros they ask for remain a lot for a cute item that you look at and enjoy, but doesn't have a real use.