Gameplay wise it's okay (Lot's of deck types to unlock, somes classes to adjust some mechanics is good too), H wise, well, aside from cards wich are very nice to look at, i couldn't find any action going on except on fizzle cards.
Gameplay is pretty straightforward for anyone who played an autobattler once in their life. You have cards, those that are doubles can stack on each other to gain power. Order of cards are read from left to right, so if you want a card that cost mana to work, you need tohave a card that grant mana before it (and be aware of the potential card that could make you lose mana).
Your task each fight is to plan the fight, by making a row that can kill your adversary, and i do mean kill, cause if you are in a tie situation (either because your or their card killed you at the same time or you took too long to get your opponent down),it count as a loss. In that scenario,making a stall deck is useless unless you have the damage to kill in like, 10 rounds (i didn't count, but sometimes either of you can't kill the other, the game calls it a tie and make you lose).
You can lose agood amount of times before the games makes you game over your run, so you can have a slow start to gain power (even if you lose, if you still have lives you can continue, and will begin the next fight upon defeat.)
When you get the hang of it winning is not so challenging, so getting all the deck would be only time consuming, unless you cheat.
Bosses on the Battle mode (wich is the standard you fight till you get to a boss, getting stronger in the process) are from the other game that the devs made, and as much as i like the idea behind it, the art design make it way of the mark (Design is as it was on the other game, while all the rest is made with AI, so it sticks out). There is no scenes or background, just some lines when you defeat girls.
I guess with how fizzle cards looks, they could reinforce the lacking H component of the game (like having a scene with each bosses, and maybe also standard opponents), as well as giving the game another purpose than slightly sexy auto battler.