Which (among other things) is the fundamental flaw of this whole setup. Here's why and also a warning that my explanation is probably going to be awful. I know what it is that bothers me, but I can not seem to figure out exactly how to express it in a written form.
If there are X enemies and they have 1 animation each, the animations get repetitive after you see them for the (insert random number) time. For me it was about 3 or 4 times and I simply just hit the skip button for the whole process. Now I am disinterested as a player and what are the chances that I am going to play the game more at that point? Not very good are they?
Sure having more enemies might help dissipate my disinterest. At this point, I might just wash my hands of this entirely and wait until I turn 50 for the "whole" game to be released. Find the game somewhere, download it, "play" it, see everything on offer, and move on 2 hours later. This is unfortunately the fate of far too many games that I see. Maybe I am doing it wrong but most of what I end up looking at ends up being decent experiences the first time through but then repetition and boredom/disinterest from the diminishing returns start to take hold. Kind of like watching the same movie over and over again and just not being as moved by the twists and turns along the way since you know they are coming.
Really its more of an issue of the games that you're playing not providing a fun enough gameplay loop to keep you satisfied. If all I REALLY came to hentai games for was to fap, well, I wouldn't be playing games and would just be watching porn. Sure, a large chunk of the reason I AM playing is because of the desire to see something lewd, but at the same time its also to interact with it in a way that is engaging and heightens the experience. When hentai/sex systems are implemented in a way that compliments the game, and usually for me it does happen to boil down to it being a con, it just makes things all the more enjoyable, though I think that's partially due to my enjoyment of the consequences of said act. However, many hentai games just don't provide enough game to keep me coming back after that fact, and so then just kind of wind up being dropped sooner or later without much desire to replay them.
Of course, then there is ones that I play every once in a while just because of the fact I enjoy the game, NoR early on was one said game and is one I can easily hop into and just go have a bit of fun dunking on enemies. Fairy Fighting was an excellent example from years ago for me, blending fighting game mechanics and hentai in a way that just... worked really. Currently I'm looking forward to seeing how Succubus Heaven turns out, as both in terms of lewds and gameplay it manages to keep me interested in just the demos they've put out really. Sure, each of these could easily be played one, see the animations, and quit, and if that's all they had on offer for me, then they'd have been long since forgotten, but the fact I do actually enjoy playing the games themselves is enough reason to keep me coming back.
Honestly its a fine balance of making a game great as a piece of erotic content, but also as a piece of gaming media, and most hentai games really don't manage to do it right, either due to lack of development time, inexperience, or just being an inferior product from the bottom up. They get a huge pass as long as they can provide something visually stimulating generally, so not many developers have a lot of reason to up the ante, but those that do tend to wind up shining through and become what is the closest thing to 'household' names we'll get in this niche subsection of gaming. Honestly, even something as simple in design as Captivity had me enthralled for a good while, and still anxiously waiting for more, and its really just a pretty simple wave based shooter with some fun and well tied in sexual systems. Easily gave me more enjoyment than a number of AAA games I've played in recent years funnily enough.
As for whether this game will wind up being much more than just a quick gallery before being dropped, hard to say right now, but I think they've got the building blocks for something really fun, combat itself isn't bad, but needs some tweaks for sure and more variety as soon as they are able. I honestly think the best way for any game to bridge the gap between allowing for on loss sexual experiences, and offering it as a reward, is to just make the gallery of the game a full unlock upon completion rather than out the gate, or upon losing to said enemy, making it a sort of 'scene collector.'