If you enter a vegan restaurant by mistake, you shouldn't complain about the lack of meat, you read the menu and move on.
That's a pretty bad analogy. A better analogy would be more along the lines of: "If you enter a vegan restaurant where everything outside the building makes it look like a basic hamburger joint except some tiny text on the sign, you shouldn't complain about the lack of meat, you read the menu and move on." and honestly, that's bullshit.
I'd complain about that restaurant's lie by omission just as I would complain about this game's outward appearance. As far as I could tell from outside the actual thread this was a game about personal training in a gym with unconventional methods (i.e. sex with trainers). From the tags, it would appear that this game simply appeals to many audiences with tags like gay, futa, furry, and monster girls with muscle girls being the main attraction due to the fact this is set in a gym. Not until the fifth image do you see the futa-on-male which is actually the majority of the game [Edit: And If I mainly wanted futa, the complaint stands but from the reverse angle. Let's say I've got a super big futa fetish and won't play anything unless it is absolutely filled with futa. Then I might have passed over this game from a short glance]. I don't take that long to read all the tags so I was unaware of the fact there even was futa-on-male in the game (i.e. it could have been futa-on-female - most common scenario - or male-on-futa since the assumed male protagonist looked fairly dominant/aggressive in that banner, and when you enter the thread, the 7th and 8th images actually appeared like that).
On that note of the MC looking dominant at first glance, this game suffers heavily from a case of inadvertent false advertising - which is why I am one of the people who really want a *Submissive Protagonist* and *Dominant Protagonist* tag because it is difficult to tell from tags if that will be the case (The male domination tag and female domination tag leads to a lot of male-NPC-dominating-submissive-MC instead of male-MC-dominating-submissive-NPC (replace male with female for the female domination version of that complaint)) - and you can't blame the people who left dissatisfied comments with this surprisingly, almost entirely, futa-on-male sex.