Very much like this game. Probably due to the fact it's based on an actual story, the characters and relationship feel very real instead of being another game about hitting the right options to get sex. The attraction and build up (even though condensed), makes the player feel much more emotionally invested than any of those other games.
Most criticisms about linearity are valid though and I feel this could be avoided if some of the game over choices are replaced with (significant?) point reduction - it would be difficult to recover from this, but not impossible.
What I'm really interested to know is whether the girl in question had a successful relationship, and how things turned out for her in general.
While playing the game I was under the impression that the author misread some of the signals which Carla was giving him. It could be due to poor translation, but I can't shake the feeling that there could have been something more.
For example, when you agree that you don't want to pursue a relationship and establish only a sexual interest, then it's normal to let it lie, but she kept bringing it up every other occasion. Conflict in the situation is added by the needy former boyfriend who appears to have taken Carla for granted. I do believe he really did love her in a way, but was immature to the point he wasn't able to see the problems in their relationship and likely wouldn't make an effort to communicate and improve. At that junction Carla, being sexually unfulfilled, tried to resolve her inner conflict by gauging if the author would be interested in an emotional relationship to complement the sexual attraction she felt for him. He, being a young adult, misread the situation and kept it strictly physical. They had a fun one-time encounter, but he missed the opportunity for something more.
Though such a relationship may not have worked in the long term, I'm pretty sure the one between Carla and her boyfriend went a lot worse. Considering her normally shy nature, she probably wouldn't talk about her sexual dissatisfaction to her boyfriend, eventually resulting in a break up/divorce as the best case scenario. Worst case, she's trapped in an unhappy marriage with children and is being unfaithful to her husband.
Anyway, keep up the good work Arizona. A lot of us are eagerly expecting your next game and I'm sure that some would volunteer to help with rendering/whatever in case you need it.