Did anyone here actually back it?
I backed it. Here's the basic gist of what's going on, as I understand it. About a week before the end of the funding phase, they figured that with a small design change, they could make the watch IPX7 compliant. What this basically means is decent waterproofing, able to survive immersion in one meter of water for 30 minutes. Prior to this, the Gameband design allowed for little to no water resistance, so backers were quite happy with the change.
The updated IPX7 design meant that the original renders were no longer accurate, so the watch ended up with a boxier design. Not a big deal, I guess. But once they were deep in the DVT (design verification test) phase, they noticed the USB-C connector was about 1mm too deep within the watch body for your typical USB-C cable to reach. Most cables' molded plastic housing would bump into the outer edge of the watch and keep the metal connector from making full contact inside. They wrestled with this for a couple months then decided, maybe, an adapter would be the best way to move forward, without starting over from scratch and delaying the project another year or so.
Then, they ran into the great wall of the Chinese New Year shutdown, halting any progress in finishing DVT or moving on to hard/soft tooling. That holiday has since passed, and they're starting to move forward once again, but details are light.
Communication has been a constant issue with the Gameband team these past several months due to a combination of factors, and prolonged silence makes backers uneasy. But it's a Kickstarter, after all, and those come with certain risks. I'm not terribly concerned, myself; I've seen videos of recent prototypes showing off the software, and I've played a little with their SDK, too. Their website shows an April, 2018 availability for some of their software, and if that's in any way indicative of the the timeframe for the watch shipping to backers, then I'm OK with that. But again, without better communication, it's hard to tell for sure.