Fuckin love the premise. What little humor is there hits right home for me and in general am looking forward to seeing this develop further.
For the current feel when playing though...
I gotta second that the current decks are not exactly balanced against one another, which can extremly heavily influences the enjoyment being had with them.
If the player chooses the growth deck, the fight will either be a landslide victories, landslide defeat or slow and grueling crawl towards death that makes the surrendur button basicly a necessity cause you feel completely helpless. The character ability itself does nothing most of the time, since it's incredibly weak without having followers of your own, most of which utilize the recoursces better with their own abilities, so when you don't have any followers and it becomes valueable to use this ability it does effectively nothing to enemy followers as the power of the ability scales with with the ammount of big followers you have on the board. It is at the best of times a win more that does nothing to help the player when they are even with the enemy and very little when they are behind, with even the win more bit being very weak. It feels like playing without an ability more often than not. Further more playing this deck feels especially bad once both sides start top decking as the player will have to either do nothing for 3-4 rounds as they are slowly being chipped down by the enemys ability or play a minion that will be nuked anyway on either enemy reaction or enemy main phase. It also doesn't help to just draw cards for a couple turns while doing nothing, cause the enemy deck will also keep drawing cards they stack in hand.
Overall I think the biggest weakness is that it is an incredibly slow combo deck that has almost no card draw and very little removal which only works on about a third of the enemy units at the best of times, while being matched up against a hyper aggro deck with a consisten way to close out the game, even if it has no more cards.
Where if the player chooses the burn deck, they will likely have a landslide victory or a tight match where victory only feels a turn or two away in some cases as they always have a win condition at the ready with their character ability. Compared to the growth deck, every card on their own pushes your boardstate closer to victory with most effects being incredibly proactive and most cards synergize far better than anything does in the growth deck. The only real way to lose with the deck is if you get hyper screwed on drawing essences and cannot start up anything, which is incredibly rare due to having a frankly absurd ammount of draw, but it can still happen. But outside of this, it feels like a super solid started deck.
The only issue I have with the deck is one card, which is the 'Shrine of Sparks' card. It's the ONLY structure card in the game as far as I know and it is not explained how it differs from the other follower cards, nor is it shown to be a Structure not a Follower when you RMB on it to show it's different as outside of being a different type it follows the exact same rules as followers, but makes it immune/untargetable to all effect that hit followers. Which, as I first encountered it while playing the growth deck is confusing as shit cause due to being a Structure it is also not affected by the Growth deck character ability and any and all removal in the growth deck.
But mechanical problems/imbalances aside, I love the general way the system works and do thouroughly enjoy the way the game plays. Having to consider balancencing which Essence cards, Followers, Reactions to use when is intutive enough and just works.
My biggest issue with the gameplay is the lack of control on where to place followers. That they allways spawn at back of the line is massively detrimentel to just going around/ignoring the big fat enemy follower in the front, cause your followers will just kill themselves each turn on it so you really can't ignore/stall them. Oh, and some effects not being explained, unless I missed them in the tutorial, like why some cards go dormant after attacking again for a turn and some don't. From observation I assumed it was cards with triggered abilities, but that also wasn't the case as some with triggers to and some don't.
Most other things are QOL things I know will come later, such as most cards not being easy or straight impossible to read in hand unless you right click them, or just the general readability of the cards being a little cluttered due to text formating. And the tutorial would be neat if it made you right click a card so it's in the middle of the screen when it explains all the values on a card for easy visual reference.
But again, what I have seen so far has me interested and hooked enought to keep track on how it developes.