Had this idea for a while now, and I'm not sure if somebody's already discussed it, but what if you could get energy as a drop? Perhaps a little less rare than Orbs and more rare than Fire Crystals, but you could get small amounts of energy dropped from treasure boxes.
It would be in increments of 1 or 2 energy per drop, with rare drops of 5 and super rare drops of 10. They wouldn't come in three's like rarities, but it'd be a slow way of accumulating energy without spending crowns. Thoughts?

My other idea was adding various boosts to the game. These boosts would be a little like the heat boost and weapon slot upgrade and so forth, but a little more common and without a need to buy them. For example, a crown booster as a drop in the Arcade, that would last for a few minutes or so, and any crowns you got during that period of time (while in the clockworks) would have their worth doubled. 1 crown is 2, 5 is 10, and so on, up to 50 crowns being 100. A similar thing would be cooldown boosts for sprites. While you have this boost, your sprite skills cooldown is cut in half for the duration. Other options could be added, like fire crystal and orb drop rate chance boosters. These would work like the attack up, defense up, and speed boost drops.