TL;DR: Heart and Seoul is a short slice-of-life about a getaway house-sitting for a relative. It had so much potential, but poor writing and static character sprites with only one facial expression make this visual novel (VN) fall below the quality of many FREE visual novels on steam.
I can't recommend buying this when there's several free VN's with better writing, better art, and more features. Still, if you can grab it bundled or on sale, it does have some good moments.

PROS
Nice soundtrack
Nice sound effects that are relevant to the story - door bell chimes, phone rings, etc

NEUTRAL
You're not able to take screenshots in Ren'Py, but the dev posted a workaround in a different game, here: https://gtm.steamproxy.vip/app/416630/discussions/0/492378806374551762/
The Art Gallery exhibit was a nice idea, but 4 paintings seemed way too short for an artist's exhibit.
Writing has a lack of continuity, the characters seem to contradict themselves in places. example: Kim Yoon-Ji says "I'm house sitting for 5 days" then later says "I'm staying here for the summer" -- Wait, what? Is your "summer" is only 5 days long?
There is a match-3 game in the story that you must play 3 times, and there is no skip option for it. I didn't mind it and found it was actually enjoyable to play, my objection is that there is no in-game benefit to playing it. It would have been nice to see Kim Yoon-Ji "earn her tips" bartending for the evening based on how well you did in the mini-game, then have later story choices limited by the amount of cash she has to spend. Better match-3 success = better tips / more money = more choices later on. I also think a "skip" option should be available for those who don't enjoy such games.
It's not voiced. This didn't matter to me, but might matter to some.

CONS
There's no steam overlay.
There's no CG gallery.
There is a log, but the typeface and the background graphic make it really hard to read.
Characters have only one static pose and one facial expression - no matter if you are having the time of your life together or if you are coldly dumping a guy after he declared his love for you, his expression never changes. I've seen far better quality on free VN's, the fact that you've charged for this is inexcusable poor quality.
The characters never change clothes for the entire 5 days of the story. Whether they are going to work, going out clubbing, going on a sightseeing tour, going to a museum exhibit, or going to confess their love to a girl - they always wear the same outfit. It really ruins my immersion in the story when the characters don't change clothes for 5 days AT ALL.
The game requires a LOT of clicking for such a short story. Every page has only a short sentence - sometimes only a single word, and you have to click through many pages read all of the characters speech. It would be much easier to read if you put all four short sentences the character was saying on a single page, but then it would be much more obvious how short the story actually is.
I found the writing style has promise, but was still rough around the edges. I feel the author could benefit most from working on "show don't tell", as far too many things are TOLD to you, rather then shown.
The biggest negative for me was the complete lack of character development, which meant I didn't really care about the characters.
Kim Yoon-Ji (the main character) isn't very detailed or thought out well. It's said she graduated university 2 years ago with business and communication degree, but she's been tending bar and working at cafes because economy is bad and she hasn't found a better job. However, it's never detailed what kind of job she actually wants, what she was going to do with the degree (her "dream job"), what her career goals actually are, or what she desires in life.
There are 2 male love interests, but neither one of the guys really had a developed personality so it was hard to feel anything for them, or care about their characters. Their characters seemed more like trope outlines.
Insta!Love. The male characters fall in love with your character SO FAST! I do understand it's a short VN taking place over 5 days, but even if I felt a major connection to a person I would not feel comfortable declaring my love after only a week. Asking someone you've met and have feelings for to stay in the area, helping them get a job and find an apartment - yes, that's totally logical to offer them. This "romance" felt somewhat forced and unreal, because I didn't have time to develop a connection with any of the characters and BAM they're in LOVE! The characters lacked enough development to stand out and individuals, as well as connect to each other. It just didn't seem like they even really knew each other well before they jumped to declaration of love.
- Park Hyun-Woo (dark hair, serious, architect assistant) says "I love you" after only knowing you for 5 days.
- Lee Seok-Jin (blond hair, wacky, DJ) says " Dam girl, you really got moves!" after you make love for the first time. (yes, it's actually misspelled in the game like that)
It's been mentioned in many other reviews, but it bears repeating - at the start of the game, you're told how this is supposed to be an AUTHENTIC Korean setting. Then you are treated to several minutes of a non-skippable club scene with pretty much only white people. I saw only one Asian male in the club scene. It's annoying and really breaks the mood of the game. Although there were mention of some Korean foods, there was also "No one does breakfast like the Americans." Overall it didn't feel like it was a story from Korea, it felt like it was a story written by foreigners about what they thought Korea *might* be like.

TRADING CARDS / BADGES
The badges are buildings. The emotes are black and white artwork, and they display clearly. The backgrounds are 2 character backgrounds and one muted city background.

VALUE FOR THE MONEY
Poor. There are FREE VN's that offer more both in terms of a longer story that is internally consistent and in characters who are better developed and have many varied facial expressions that match the events of the story as it unfolds.
You're better off reading any number of other quality free VNs before you spend money for this.

TL;DR: Heart and Seoul is a short slice-of-life about a getaway house-sitting for a relative. It had so much potential, but poor writing and static character sprites with only one facial expression make this visual novel (VN) fall below the quality of many FREE visual novels on steam. I can't recommend buying this when there's several free VN's with better writing, better art, and more features. Still, if you can grab it bundled or on sale, it does have some good moments. PROS Nice soundtrack Nice sound effects that are relevant to the story - door bell chimes, phone rings, etc NEUTRAL You're not able to take screenshots in Ren'Py, but the dev posted a workaround in a different game, here: https://gtm.steamproxy.vip/app/416630/discussions/0/492378806374551762/ The Art Gallery exhibit was a nice idea, but 4 paintings seemed way too short for an artist's exhibit. Writing has a lack of continuity, the characters seem to contradict themselves in places. example: Kim Yoon-Ji says "I'm house sitting for 5 days" then later says "I'm staying here for the summer" -- Wait, what? Is your "summer" is only 5 days long? There is a match-3 game in the story that you must play 3 times, and there is no skip option for it. I didn't mind it and found it was actually enjoyable to play, my objection is that there is no in-game benefit to playing it. It would have been nice to see Kim Yoon-Ji "earn her tips" bartending for the evening based on how well you did in the mini-game, then have later story choices limited by the amount of cash she has to spend. Better match-3 success = better tips / more money = more choices later on. I also think a "skip" option should be available for those who don't enjoy such games. It's not voiced. This didn't matter to me, but might matter to some. CONS There's no steam overlay. There's no CG gallery. There is a log, but the typeface and the background graphic make it really hard to read. Characters have only one static pose and one facial expression - no matter if you are having the time of your life together or if you are coldly dumping a guy after he declared his love for you, his expression never changes. I've seen far better quality on free VN's, the fact that you've charged for this is inexcusable poor quality. The characters never change clothes for the entire 5 days of the story. Whether they are going to work, going out clubbing, going on a sightseeing tour, going to a museum exhibit, or going to confess their love to a girl - they always wear the same outfit. It really ruins my immersion in the story when the characters don't change clothes for 5 days AT ALL. The game requires a LOT of clicking for such a short story. Every page has only a short sentence - sometimes only a single word, and you have to click through many pages read all of the characters speech. It would be much easier to read if you put all four short sentences the character was saying on a single page, but then it would be much more obvious how short the story actually is. I found the writing style has promise, but was still rough around the edges. I feel the author could benefit most from working on "show don't tell", as far too many things are TOLD to you, rather then shown. The biggest negative for me was the complete lack of character development, which meant I didn't really care about the characters. Kim Yoon-Ji (the main character) isn't very detailed or thought out well. It's said she graduated university 2 years ago with business and communication degree, but she's been tending bar and working at cafes because economy is bad and she hasn't found a better job. However, it's never detailed what kind of job she actually wants, what she was going to do with the degree (her "dream job"), what her career goals actually are, or what she desires in life. There are 2 male love interests, but neither one of the guys really had a developed personality so it was hard to feel anything for them, or care about their characters. Their characters seemed more like trope outlines. Insta!Love. The male characters fall in love with your character SO FAST! I do understand it's a short VN taking place over 5 days, but even if I felt a major connection to a person I would not feel comfortable declaring my love after only a week. Asking someone you've met and have feelings for to stay in the area, helping them get a job and find an apartment - yes, that's totally logical to offer them. This "romance" felt somewhat forced and unreal, because I didn't have time to develop a connection with any of the characters and BAM they're in LOVE! The characters lacked enough development to stand out and individuals, as well as connect to each other. It just didn't seem like they even really knew each other well before they jumped to declaration of love. - Park Hyun-Woo (dark hair, serious, architect assistant) says "I love you" after only knowing you for 5 days. - Lee Seok-Jin (blond hair, wacky, DJ) says " Dam girl, you really got moves!" after you make love for the first time. (yes, it's actually misspelled in the game like that) It's been mentioned in many other reviews, but it bears repeating - at the start of the game, you're told how this is supposed to be an AUTHENTIC Korean setting. Then you are treated to several minutes of a non-skippable club scene with pretty much only white people. I saw only one Asian male in the club scene. It's annoying and really breaks the mood of the game. Although there were mention of some Korean foods, there was also "No one does breakfast like the Americans." Overall it didn't feel like it was a story from Korea, it felt like it was a story written by foreigners about what they thought Korea *might* be like. TRADING CARDS / BADGES The badges are buildings. The emotes are black and white artwork, and they display clearly. The backgrounds are 2 character backgrounds and one muted city background. VALUE FOR THE MONEY Poor. There are FREE VN's that offer more both in terms of a longer story that is internally consistent and in characters who are better developed and have many varied facial expressions that match the events of the story as it unfolds. You're better off reading any number of other quality free VNs before you spend money for this.