40% of the work does not mean 40% of the game. The easy part is adding content, the hard part is making all the stuff work properly in the game. From what we have seen so far things are not working properly in the game. It's like saying, Its hard to paint a wall, most effort goes into painting the wall, then the rest of the time it just needs to dry
Also worth saying this, 80% of the time goes to developing the final 20% of a product

If he is 40%. He hasn't gone into the really difficult hurdles yet.
This.
This is the actually my greatest issues with this first release release. We are not talking about a single dude doing this after work/school. It's a guy with 1+ years of experience in this sort of thing, with thousand of patreons, with goals like quitting his job to do this full time and hiring help achieved, and who has gone kinda quiet for months on end, with mentions of how a new engine is really needed for their special vision.
And what we got was something that does basic scene progression, moving between rooms and triggering events on click. This isn't anything we haven't seen before in the most basic renpy game but more buggy and lacking some basic QoL options.
Bugs can be fixed, but if this all that the engine can do right now it's kinda bad and I feel sort of sad for doing my part in bankrolling them these months when they could have just made a great renpy game. If the engine can do more they should have included a more open sandbox part with just filler content to give us an idea of we will be able to do.
If not, they at least could have tried to put more content in. Right now it feels like a 'get off our back' release to shut up the patreons.
This release would have been amazing for a new guy/team. For Lewdlab, after all these months, it feels sort of lacking sadly.
Other than this it looks kind of promising.
The girls are great. I love the mom and teacher (though the mom should have been a little closer to the teacher in cup size). The sisters are great. All the other ladies are ok I guess, but they didn't leave an impression. We also need a aunt with the same body type as mom but with bigger tits

.
The writing is a little cringy, but I'm not here for Hemingway. The main character is presented as a huge douche, but it makes sense since Dr Sin wants him to grow as a person.
On the other hand I do really dislike him perving on the family so fast. 5 mins into the game and he's already rubbing his dick on family members he hasn't seen in years. He's a player who knows his ways around the ladies and wouldn't have problems getting chicks, and also doesn't have an excuse like the magic spell from DoD to cloud his mind.
For the people that are afraid of too many males in the house/NTR, I'm pretty sure the main plot will require the father to go away in some form or another. There was a preview of an older looking dude from Lewdlab and I'm pretty sure that will be the evil rival who will try to take over the business once dad is gone and our job will potentially be to defeat him and provide for our family (in more ways than one giggity).
I don't know how the twin brother fits into this but he could probably grow envious when dad gives us an equal chance to run the company and probably conspire with the evil dude while in order to stay in charge.