Card Quest is alright in concept, but it gets incredibly stale really fast.
This is a card game, but not really a deck building game because all the cards are tied to equipment which is selected at the start of the run and never changes unless the player unlocks something new, and even then that's usually a terrible idea since it will ruin your current build.
Equipment can only be unlocked when the player clears an area for the first time so unlocking more equipment requires going through early game areas again every single time. As a result, Card Quest is incredibly grindy. Don't think for a second that the game can be cleared with default gear either because you can't even fill all the equipment slots from the get go.
Card Quest could have been good if it wasn't designed to waste the player's time. I mean each campaign is lengthy for a roguelike at around 3 hours and there are 4 playable classes with 3 subclasses each so that's a lot of gameplay. There was no need to pad it like this, but they did it anyways. It's just frustrating.