Combat cards are cool, fun to find and teach to people. It would be fun to have a little more strategy (cards that have specific uses, bonuses vs specific creatures, or more strategic abilities) to add some nuance to the "open a color and attack" system we have.
Stomp: if wearing boots, deal 5x damage to small animals: ants, snakes, etc
Sneak attack: add bonus damage based on stealth difference
Opportunist: add bonus opening based on stealth difference
Fight dirty: add bonus based on stealth difference, scent length doubled if vs pc
Soothing tone: accept full damage of attack, if opponent is tamable add X to tame score based on husbandry
Strategic retreat: accept full damage of attack, move pc one square away from mob
Monkey grip throw: create opening based on opponent's attack color, bonus for mobs larger than PC
Seven sided strike: each time this card is used it hits an additional cumulative nearby mob (must be unarmed)
Exploding palm: if used when its color is at 100% or more, causes X ongoing bleeding damage to target (must be unarmed)
Knock out of the sky: if target is flying, create slight openings in all colors and remove all its IP
Called shot: nearby ally gets bonus opening
etc
I think most of us eventually end up with the most useful cards and there's basically just one way to attack for almost everything we encounter, eliminating interesting choices. Perhaps allowing a character to create a "deck" of cards, and each round you have several to choose from, would make combat interesting.