I know that I am probably asking tooooo much with this post, but I am thinking of an idea that could increase the number of players and help also on the funding of the game.
Based on the same New Year promotion idea you had, I would place a list of dates-development implementation that can be listed by the ammout of donations.
So something like:
...
$10K - underground minning implementation - 2 months after this achievement
$20K - new weapons (damage types,.....) - 1 month after this achievement
$30K - new armor (damage absorbed,....) - 1 month after this achievement
$40K - new tools (mining, picking, axes,....) - 1 month after this achievement
$50K - Vehicles introduction - 3 months after this achievement
...
...
Even place an advertisement in Kickstarter. By donating certain amounts you can get specific benefits:
...
Just like you did with new years promotion
...
Maybe this will help people to donate more money to support the game

and the kickstarted advertisement make more ppl join the game!
With my best regards,