I played for the plot.
I don't have much experience with 'lewd' games. This one was recommended to me by a good friend, who promised me boobs as far as eye can see. He didn't disappoint me, and neither did Summertime Saga.
I played for about 144 days of ingame time, which seems to have covered all of the content currently in the game. That's many, many hours of interesting and fun gameplay. The first time I started the game, I couldn't help but keep playing. I actually lost any sense of time and before I noticed, it was already night time. The author of this game seems to know a lot about various kinks people have. He implemented them so well, that I felt compelled to keep playing and discovering new degenerate fetishes I never even knew existed. Some of the characters straight up dare you into finishing their quests, they bully you - they call you names, treat you badly and laugh at you. Yet you keep playing, because deep down you know you get to fuck them later, almost as a payback. Don't be fooled by boobs, this game is about conquest. You conquer one 2d woman after another - you destroy their relationships, sabotage them and take advantage of them - all while they praise you for being a good guy. If you asked me what I love the most about the game, I would say it's that most of the time it gives you an option not to pull out. So I never did. There were no survivors. As far as I know, half the town could be pregnant right now.
Having said all of that, there are ways Summertime Saga could be improved. Some of the minigames could be better, and some quests are as simple as going to a place, clicking a thing and then going back. I'm sure there's a way to make these more engaging for the player. I really enjoyed the rap battles, but basketball was just awful. I think minigames and quests need some more work.
Also, there doesn't seem to be any anal in the game. The only instance I can remember (which also barely qualifies) would be the double sybian scene. I named Jenny in the game "Buttslut". Imagine my disappointment when she couldn't live up to her name. Among all of the weird content I found in the game, I was really surprised that there wasn't any good old butt stuff. And even though I love boobs, I feel like the game is way too focused on them. Please show some more love and appreciation to butts, feet, hair, lips, or even armpits(?). If I can get my aunt pregnant just so she can produce more breastmilk for half of the town to consume, I feel like I should also be able to pee down my sister's throat.
Go all the way and don't focus so much on boobs. That would be my advice.
I'd also like to add that I'm not good at writing reviews, so please don't crucify me. I also hope the words I used are okay with your rules.
Overall I would recommend this game to anyone who likes a good mix of porn and comedy.