For me, it really depends on how its done/the associated fetishes. I don't really want an MC that's infantilizing himself or whatever. I'm more into a "this is a woman I love and want her to be a part of me" kind of thing. Which is, unfortunately, very rare in games that include lactation.
As an extra to a game that is not primarily about related kinks, it should always be optional. A good example for doing this right is in a recent update of Maids and Maidens. The MC is subjected to an initiation ritual at a sex cult called "The Family". When "the Mother" offers him her breast to drink from, we have the option of being reluctant. In this case we are told that it's enough to just symbolically nibble on her breast.
Doesn't do it for me at all personally. Maybe if they didn't always gush gallons of the stuff...I don't know. Also don't really love the huge tits that seem to usually be a part of lactation in games.
breast milk isnt really done that well in any kind of porn. but maybe cause its one of those more sensory than visual things. with the exception of seeing a woman lactate a drop or two when verbally stimulated alone, its a complete waste for milk to come out of a breast and not directly into a mouth. the sensations of drinking breast milk while doing everything naughty under the sun is quite invigorating. personally the milk tends to drive me further into lust, and ive been cursed at many times for not leaving any for the baby.
for me breast milk is cool but its something i want to consume not see, so im meh in porn and vn's. though it is completely necessary to show a drip of lactation from the breast when theres milk otherwise you wont know if there is any.