IMO the reasons this game has gained popularity so quickly is because its different, in good ways, to other games. People like that.
- MC is a star athlete who is a very nice guy but not a pushover. How many games have that? I can't think of any MC's like this one. The star athletes in other games are usually assholes, nice guys in most games get stepped on. This MC is different. He is the leader who won't take shit, but he is also a caring and all-around nice guy.
- This is a harem game, but how many harem games have the GF be the one to push the harem? None, Jamie is unlike any GF in any game. In other games, you have to cheat in order to get the girls. This one you don't, she quite literally tells you to get more girlfriends and when Shauna joins in, she does too. Shauna is also a very well done trans character.
- The other guys, namely the other players, are well done. In most games, the other male characters are competition, or they're used for NTR or whatever else. Especially the black guys, but this game doesn't give off any of those stereotypical vibes like most games with black male characters.
- Unique pregnancy "job". MC in this can basically be a sperm donor, so for people who like that fetish this is a must play. Typically, that content is just used in the later stages of the game but in this one its there at the start.
- Lots of different body types and personalities. You have busty MILF's, you have petite girls, you have cheerleaders, you have emo girls etc. If you like a specific "type" of girl, she is probably in this game. Most games simply don't have variety, this one does.
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Obviously, the models are nice. The story is nice, but there are other games with those things that don't take off. This game does some popular things differently. people are tired of playing the typical " MC with 2 roommates and a landlady" or "Pervy college kid" games. Hopefully this game can be inspiration for other devs to try something different.