This is another entry in the Suburban Harem subgenre of porno games. In this subgenre, you're an unassuming young man of non-descript general attractiveness. You're fit, slim, and are of average abilities and intelligence. Your only immediately noteworthy trait is your large dick. You cohabitate with a doting milf type, and usually there's a bitchy older sister archetype that's simply a younger, but sluttier version of the aforementioned milf, and sometimes there's a younger sister who adores or idolizes you. Additionally you might spot a girl-next-door type, or an auntie who is a sluttier version of the milf but of a comparable age. The father is absent, either because he left or he died, and this provides a through-plot for the entire game.
In this case, Resident X in its current state fits the bill- you are an unassuming, good-natured young man with a big dick who cohabitates with a doting milf. Your dad is dead, and in this case, he was messing with some secret society, alien stuff. There is an absent sister type, but she's hinted at and will 100% appear should this game keep being updated. There's a girl-next-door and an auntie-esque hot teacher.
The art of the game is the high point, but I suspect it may be the reason for the snail's pace development. This game is over a year in development at the time of this review, and there's barely any content to speak of. There are a few scenes, but unfortunately it feels bereft of stuff to see compared to its peers within this subgenre.
Gameplay wise, I will give it points for having a good quest-log, logical puzzles and a good sense of direction. I didn't have to consult an external guide to progress. It's typical Ren'Py point-and-click, inventory management gameplay, but honestly it stays in its lane and doesn't try to do crazy stuff with the limited engine. It knows what it is, and that's good.
So, maybe check back in 6 months to a year to get more of a completed experience. If it keeps on track, it'll definitely be a 4/5.