As far as deck-builders go, My Card Is Better Than Your Card! is definitely more on the cute side with you crafting cards from stickers you collect. Currently in Early Access from Utu Studios, it has a genuinely lovely idea for a turn-based card battler. Note: the developer sent GamingOnLinux a key.
Here pretty much every card can be completely unique, because there's no standard set of cards. While you do get an initial deck to play with with some basics, everything from then on is entirely down to how you want to play. Cards are built by stickers you find digging in the sand (who is burying all these stickers?) or buy at a shop from coins earned through battles, and each sticker has its own effect. You can load up cards with lots of these stickers to make them quite ridiculous but they all come with a cost attached to play.
Candy is the cost / mana system here, with each card having a candy cost depending on what stickers they have. You start battles with a small amount of candy, and each turn you can pick to boost your candy amount or draw an extra card. Then it's down to the battles.
This is where it's also quite unique, as the battle system is a bit of a tug-of-war. Instead of a health bar, you have a star meter with a total one of you has to hit. Each player builds up stars during a turn by playing cards, and then whoever has the most at the end of both turns will have their stars added to the meter (minus the amount of stars from your opponent) to progress towards one side. So if you have 10 stars, and your opponent has 6, you get 4 stars added to the meter towards your opponent.
There's also a special fever meter, which over time adds a multiplier to the total stars you have at the end of a round. This is pretty much essential, as otherwise battles might end up going on and on forever since it's a tug of war.
While it may look incredibly inviting from the visuals and setting, it's really quite a challenge. You have to pay such close attention to all the stickers, because you can really stack up some insane combinations with them and end up getting tons and tons of stars every round.

Direct Link
Really loved what I played of it, but they really do need to be careful on the balance of the stickers to make the cards, because even early on in the game it can end up a bit more challenging than it needs to be while it's easing you in. Aside from that, it's a brilliant idea with great presentation.
Really fun to play and create cards and I'm looking forward to seeing it finished. Works perfectly on Linux with Proton 9. Definitely one of the most interesting deck-builders released in the last few years.