I really wanted to like Research into affection more than I ended up doing so, but at the very least, I know what it is that caused me to dislike it, and it's possible that you may feel differently.
The characters are interesting, if not a little one-dimensional. The two main love interests, the mother and sister of the main character, are all that I will discuss here, as thus far only one other girl is able to be raised beyond level one. The renders are fine, and the poses and camera placement are pretty good for a honey select title.
The sister is fun-loving and likes pranks. The mother is really nervous about having an inappropriate relationship with her son. Both of them love the Main Character, in a familial way to begin with, and eventually more romantically. (Which basically means that eventually they will get over you walking in on them in the toilet and don't immediately tell you to get out.)
The game interface is mostly clear. A menu bar has some shortcuts and access to the diary, and the primary interface is just clicking on a location where a girl is having an activity too join them or talk with them.
The implication that you will need to balance time on working on your patreon and seducing your family is interesting, but misleading. The only uses for your funds is buying outfits, going on dates, and installing spy cameras, but the cameras are optional, (and mostly pointless) and the dates and buying outfits are just momentary hurdles to progression.
PROS
The diary system as a checklist has promise -
The diary entries were interesting, and after each scene was viewed for the first time, the inner thoughts of your mother or sister would be conveniently written out for you to find in their journals. These were occasionally interesting, but almost never surprising, as they only wrote about the scene you just had, and mostly along the lines of "OMG, you will never believe what we just did..."
The graphics are pretty good -
Hey, look. Animations. And they don't totally suck. The videos of most of the lewd acts are fine, once you get to them, and better than the still frames that a lot of lewd games favor.
CONS
This game is repetitive -
To progress in the game, you will need to grind out stats with your mom and sister to make them affectionate towards you. 5% affection per act (with a few exceptions) means that it will take about 20 actions to get them to 100% which unlocks the ability to buy them a dress and take them out on the weekend. Some activities get progress for both of them, but mostly, that will be 20 acts per girl. (You can fast forward through content you have seen as per usual renpy rules.) After you go on a date, which required you to max out their affection, you are frequently rewarded with a large bunch of affection, which is all lost. Then, after you take each on a date, the three of you watch a movie together, and you reset to 0 affection at the next level. This just seems asinine from a game perspective. Spend time to make them love you, date them for a reward that is useless, and then remove ALL progress for the next arbitrary hurdle.
This game is repetitive -
That same diary system that tells you which scenes you have seen, can be used to find the scenes you miss. If you decide that you want to see them all and have them checked off in the diary, you will need to progress through around three game weeks for every week of story progression. So every week of new scenes, takes about a month in game. Every day activities like going to school and going to work can have all the content viewed in 2 days. but for the weekend, 8 activities will be packed into the 10 o'clock slot. (to be fair, only 4 activities count in the diary) But on top of the optional morning activities, 2 extra options are required for progression. 6 of them are either barging in, peeping, or knocking to get a scene. A few other weekend scenes will change, but they can mostly be viewed in only a single weekend. What this means is that in order to fill out the diary that the game keeps like a checklist, you will go through one game week and see the vast majority of available scenes in about 2 game days. Another 4 game days will let you unlock the diary options for the morning routine. (you can barge in, peek or knock while mom and sis are in the bathroom or shower) But because the weekend 10 am slot has those same peek-open-knock options, as well as an option to invite out on a date that evening at 5, and you can only do two actions out of 8 each week. What this means is, with less than 1% new content after the first week, each game level will take you about a month of gameplay to not skip a scene.
This game is repetitive -
Not only will you see many scenes repeatedly, but all the scenes blend together into a banal conversation "Tell me what you want." "I want to go slow." "OK, we will progress slowly." for the entirety of gameplay. While the sex acts and lewd scenes do progress, there is no variety to the conversation they will have about what they are doing. The MC tells mom he loves her tits early and keeps telling her in every scene where she is topless. He tells you that he can't believe how comfortable his mom and sister are getting with him every time either shows him anything. He tells his sister he will get even for her latest teasing every time she opens her mouth. The fact that EVERY sex act you had to grind to unlock is met with at least FOUR scenes with dialogue like
Her:"You know that thing we did before? I liked that"
You: "We can do that again"
removes any interest that a hot steamy scene could possibly have. And while I could have complained about the writing here instead of making the repetitive joke, the fact that SO much of the conversations sound like they were copy-pasted from conversations that you JUST had is really a crime.
The game is really fond of making you repeat scenes you had watched before, making you repeat every conversation you have at least four times, and making you repeat all of the things you just did with one of your family members with the other one. I could complain more, but I feel I would just be repeating myself.