This game... I like the art style and the animation. The writing is alright, too. Unfortunately, the core game at the center, the card game is. Oof. Wow. So fucking bad you have no idea.
So basically, the card game is rock paper scissors with a few twists. You pick a rock, paper, scissors or special card from your hand without seeing what your opponent is playing or even could play (except for if you get a buff I'll talk about later). Each card has a value. If your card beats the other card's type, you deal that card's value in damage to them. If your card loses, you take their card's value in damage. If your cards are the same type, whoever has the higher value deals damage. Special cards always take damage from the opponent's card, but always deal damage, too, or you can have them heal you for their value instead of dealing damage (more on that later). You win if you either reduce the opponent's life to zero or they run out of cards to play without reducing your life to zero. You lose if either of the same happen to you.
In addition to card behaviors there's a few other mechanical twists. If you play 2 losing cards you get to see what your opponent's next card play will be. Your opponent, if they lose twice, will also get to see what your next card play will be, which essentially means that you're guaranteed to lose at least one out of every three plays, since they'll beat your play as long as they have a card in hand available. The special cards are a way around this mechanic, both for you and your opponent, but if you mean to use them for that your deck needs to be roughly 1/3 special cards. There are one-time use items you can receive for winning battles, along with receiving cash and XP, and those one-time-use items let you do things like make a card unblockable, deal double damage, or make it so you only need to lose one hand to get your prediction powers (I may be misremembering one or more of the item effects, it largely doesn't matter because the items are a bad idea, a mechanic that *could* be a comeback mechanic but ultimately only helps out players who are already doing well).
When building a deck, you are limited in how many cards you can put into it. Each card costs a certain point value equal to the card's attack value, with special cards costing double their value. This means if you want to hit the "1/3 special" sweet spot you're spending a ton of your points to do so, so you're probably not going to hit it if you want to keep a deck that's big enough to not regularly lose by running out of cards. It is possible this is, in fact, not a sweet spot and I'm overestimating the need to outplay the opponent. Maybe it's cool if you just take damage on one third of all your turns. You have life points, after all, and the only one that matters is your last one, so may as well tank a few hits? Even still, the use of special cards to mitigate the harm of those turns seems important, and like it was a core design consideration, which is problematic since using them that way is mechanically prohibitive.
In this game, much like in Magic: The Gathering and other similar card games, Lifegain just delays the inevitable, and if you don't have inevitability on your side, usually delaying it isn't going to put it on your side. There are ways you can design a game so that is not true. Sugar Service has not done those things. It seems like the devs are not even familiar with the concept of "inevitability" in 1v1 turn-based, life-point based games.
The game is mostly a VN, but to get the next scene with any of the characters you need to buy them gifts. To get money you need to go on "dates" (card battles) with unnamed, unseen characters, and you need to win. You can't spend money to get one-time-use battle items, only to buy card booster packs, gift items for girls, or to improve your stats. Your stats don't currently appear to do anything in unlocking scenes or in battles, rather at the end of a battle you discover what your opponent's "favorite stat" is and then get bonus money based on how high yours is. At the end of battle. Meaning you can't choose your opponents based on who would be most rewarding based on your stats. The whole game is full of little decisions like this, ways that they make the game's other mechanics feel pointless or random.
And the pointless randomness is the big problem! At its core the battles are rock paper scissors, meaning you're only winning about 1/3 of the time. The tools to mitigate the randomness are only given to you if you're already winning, the "dates" (random battles) scale up with your level so you can't reliably grind against weaker opponents, meaning if you buy too many gift items and don't keep up your card deck you could easily softlock yourself by having a deck that's too weak to beat anyone and not being able to buy more cards for it. There are cheat codes you can use to just give yourself money, and I recommend using those, but even then you still have to play the card game when you're going on story dates with the main cast girls, so you still have to interact with the game's incredibly random and incredibly unfun card game. It's all just a pile of bad decisions that there's no quick easy "just do this' fix for. I'd say the best fix is "don't base your core gameplay around rock paper scissors" but that ship has already sailed.
If I were to go about starting to fix the card game I'd probably make there be cards that do more than just basic things? Cards that let you draw other cards, cards that can block specials, cards that can lifesteal or guard break, cards that let you put some played cards back into your deck (and then exile themselves from the game afterwards to prevent infinite looping). Just... something to make the card game less basic, more strategic and less random.
