Very fun- surprisingly strategic, and discovering the synergies of different characters with certain cards was quite fun! On my best run, I got up to 23 Magic Shields at one point as Elena, and had figured out that strategic triggering of Dynamite cards allowed me to destroy Toxic Mushrooms without getting poisoned. Then I promptly stepped on a Purifier...
Some things I love:
-All the different relics! They really add flavor and originality to the game.
-Strategic interactions like the previously mentioned one with Dynamite, including:
Attacking mushrooms/Pyros to reduce the cooldown of your spells, or because one of your relics is about to trigger
(As Elena, since I mostly play as her, but I'm sure this applies to other characters too) Scanning the field to figure out whether you can afford to activate your lower-level skills (Magic Shield), especially since for Elena that gives a stacking benefit, or whether the situation is bad enough to warrant your ultimate (Firestorm).
Maneuvering to a position where you can trigger that Spear Trap at an enemy
Figuring out which hits you can afford to take and which you can't
Moving carefully, keeping the cards in mind, so that you don't get stuck in a corner with two enemies that can both one-shot you -_-
Trying not to trigger a Relic Dealer/Retired Knight until you have enough gold
And some things that are just fun:
Getting saved by a relic that you forgot you had
Waiting until that moment your ultimate is finally ready to trigger
Magic Shields, especially as Elena. See above.
Anyway, I think that's it! Looking forward to unlocking Wispwood Forest!