Unfortunately, I have to rate this game as "terrible". Good things first:
The story is captivating, the humour is fantastic and I really enjoy to read the dialogues, which rarely happens in a VN with lots of text and not so much lewd scenes.
And I could, thanks to this entertaining quality, look beyond that the graphics are outdated (like, really outdated. MC's dick looks like he is a woman with a dick glued to his body).
But here's the catch, and that's where Once in a Lifetime fails miserably as a game:
I was just asked by one of the LI's whether or not I love her. So I checked this thread to see if that decision locks some routes. Then I remembered, that there was a menu where you could see on which routes you are -> I opened it for the first time and, shockingly, found out that almost all routes are "lost", I have only 2 open. That means I am missing out on content with 5 other characters (out of 7 in the entire game), which two of those being your mom and sister, which is pretty much core content! That's where the entire game is built around. I was wondering when things with them would finally happen, apparently never.
Now you might say "well, then you made bad decisions" ->That's incorrect. I always picked the choices that we're pro-whatever-Li was in front of me. There were no conflicts between two LI where a choice is good for one and bad for the other one, that could've caused that
What does that mean? Well, it simply means that the game does quietly lock you out of entire paths and a lot of core porn content without you noticing, by absolutely minor decisions that would never ever shut down a relationship (there wasn't even little things like saying a stupid thing that made someone feel bad or so!).
I can't stress this enough: Games that lock you out of content are badly designed. And games that require you to use a walkthrough because the contents don't behave intuitive and come naturally to you, it's even worse.
I'll have to think of whether or not I will continue this game, knowing that I will only see 1, max 2 girls, although there are 7 in the game and they're constantly around me (like mom and sis) and I always treated them well and went all in with a positive relationship with them. (Edit: I stopped playing the game and uninstalled it. I was pretty far in).
As a pure VN the game is good, but as a porn game it fails unfortunately. A disappointment this big can only be answered by a 1-star rating.