The main "shiny new thing" to be introduced is the concept of charged weapons: a weapon tile can become electrified to empower its next attack with bonus damage and chaotic energies that arc through adjacent enemies as well. This is like a new resource to gain and spend, but instead of a number that goes up and down it's stored on the tiles on the board. It creates a whole new range of possible board constructions. With the extra damage it's kind of an alternative to Whetstone; hitting multiple enemies it's kind of an alternative to important board-clearing weapons like Echo Harp and Witchpact Blade; and with a variety of effects triggering off it it's kind of an alternative to curses for building combo boards.
What kind of combos? Time for some EXCLUSIVE PREVIEW CONTENT oh no!
The Lightning Rod basically moves a charge from something above it on the board to something below. (You might as well put it in one of the middle rows.) What goes on top? Something has to create a charge in the first place; this is strictly a combo weapon. What goes underneath? Pick any weapon, maybe there's something you think will benefit especially well from becoming charged. And in the middle - it charges itself along the way so that's a bit of extra damage too.
And of course we have also a new alchemist hero who can manipulate charges, empowering her weapons for extra damage:
"At night" is just a fanciful way of saying "every second screen". Remember how the walls are darker sometimes? That's night-time. At one point I thought this was going to be a whole big thing, I was designing all these cards that had special night-time effects, but honestly "this doesn't work half the time" isn't a very exciting hook so forget it. But for an enemy bonus it's solid, it creates a rhythm alternating between business-as-usual and fleeing-in-terror, it totally changes the tactics around when you want to score a gem. And with both the hero and the enemies boosting damage the stakes are high; this is a challenge for skilled players.
Most of the new stuff revolves around charges, but there's a few other weird little toys to play with too. Alternative ways to score gems, to level up your weapons, to play it safe or to gamble everything.