My Gem had the same hung-up at logo issue. My Gem's battery was drained to zero. It had to be re-charged.
The following necessitates a full restore. Remember to save your device's NVM file because you will be re-flashing it anew.
First, download and install Planet's flashing files (drivers and tool). Have the flash tool running and waiting.
*With the USB cable connected to your Gemini, but NOT YET to your computer, press and hold the Gemini's Esc key while fast-tapping its sliver button as many times as necessary for the device to begin rebooting.
When its reboot begins, IMMEDIATELY connect the Gem's USB to your computer. It should (hopefully) then recognize your Gem and start the flashing restoration.
IF THAT FAILS, as it might, then disconnect your Gem from the computer.
Next, delete all of the (unusable a second time) flashing folders and files from your computer.
Next, using some free cache and registry cleaner like CCleaner, deep clean your computer's "registry" and "Clean" functions (two processes in CCleaner). NOTE: Before running CCleaner, check all of the boxes under "Applications" and "Windows" tabs EXCEPT the the bottom three choices under Windows>Advanced. Run CCleaner.
After CCleaner or some such tool does its business, reboot your computer.
Again, download Planet's flashing folders and set them up, again. Those files / tools are not reusable in my experience because they leave tracks that must be wiped away for a fresh attempt.
Repeat the above steps (see * ) and your Gem will eventually be recognized and flashed.
BTW, I did the above three times before the re-flashing found / recognized my Gemini and the restoration / fix process worked.
I don't know why that was, but it finally flashed on the third try.
All is not lost despite it seeming a lost cause to restore your Gemini.
Good luck.
IFanafi
UPDATE: The first update try using the latest, revised update tools caused my Gem to freeze at the spinning logo screen. It could neither be powered off nor rebooted.
So, I let it sit overnight which drained the battery to zero.
The next morning, when I connected the device to power / to be charged, the screen showed the large, empty battery image.
That is how I knew the battery was dead.
Many hours later, it was fully charged (so displayed the 100% charged battery image).
Still, however, it would not power on.
From there I began the succession of update failures and steps described above... until the Gemini, at last, was updated / restored to factory settings.
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Have anyone an idea what should happen or advice how to fix it (if it's fixable).
The last time i bricked mine was while flashing when I started the battery was at almost 100% but the bugger just wouldn't boot, I had some communication with Planet and they suggested holding the Esc & silver button in for at least 10 seconds, well it would start and die.
Eventually I got it to work and found the battery was at 0% even though it'd been switched off and when it was dead I plugged the charger in but no LEDs lit up. It wouldn't boot at all if plugged in so I had to get it booting and plug it in during the boot, I then had to muck about with a factory reset, another flashing and installing everything, again.
So after that preamble I'd suggest first making sure the device has enough power to get through the boot sequence, try holding both buttons down for a while - good luck.
You might find the fast charger wont do much if the battery is too low but plugging in to a PC seems to get some charge across - not 100% on this but it seemed to work for me.
I'm pretty sure, that it's not a battery problem. In off state gemini shows 100% battery.
The problem is, that i'm unable to boot anything (including recovery mode).
After initial planet logo display starts blinking and that's all.
