Nikararia Night Lessons oozes style with its retropunk atmosphere and music. Seriously, I could leave the game open and idling just to have that soundtrack play on repeat. The characters are well developed and the conversations that are had feel meaningful and relevant. I can definitely tell that some love went into creating this game, resulting in a product that is a step above the competition.
That being said, the disappointing aspect of this game is how little content there actually is, and how difficult it is to find what IS there beyond the most obvious routes, love / NTR. The overworld where you travel between different locations feels unnecessary and kind of wastes time, especially when replaying to search for other content as you find yourself just clicking through each location over and over searching for the trigger that brings you to the next scene. When you're on a character's route, there is no interacting with the other characters, so it doesn't really seem like we need to have the ability to go to other locations at all because there's nothing to do at the other locations anyways when the only one that matters is the one containing the next event in the sequence of events, there aren't any branching events that happen at the same time, at least, not that I can tell after having played through the game a few times now. It is possible this might change in the future, at which point I'd say it'd be fine to add an option to pick between going to location X or Y, which will change the sequence of events or open up new scenes.
Finally, on to the erotic content itself. Honestly, it is kind of disappointing. While the CGs themselves are certainly well made, there just isn't much of it. You either get the good ending or the bad ending and that's that, one main CG set for the endings and then you move on to the next character. I would absolutely love more time with each character individually, more scenes, with paths to those scenes being a little less convoluted (it's hard to tell what effect some of the dialogue options are having on the sequence of events and which ending they will lead to).
All in all, this game has some serious potential, and even if the issues I brought up aren't addressed, or changed in any way, it's still a great little experience and worth checking out.