OOof tell me about it, that last 3am night left me dead, I think im still recuperating lol!
I think is pretty normal now a days specially in the anime circles to include fan service in some way or another, I think most anime i've watched had those tropes lol. Is not necessary but we all know it sells specially among young people. That is why Shonen jump has beautiful women in all their manga's usually. I know steam has tons of echii games lol.
As for promoting the game, I usually try to make sure all the tags are set right, the description is clear and concise, having a decent arrival page for the player, being consistent in quality and execution of the stories. Making contacts in Discord and posting your game in a lot of discord channels that allow promotion. Oh and having an active twitter has also helped.
I also realized since my games Clicker V and Fear Me got a lot of good hype form those last two competitions, they give me spots on their fresh games sections so people see them sometimes. I think having a présense all over really helps with visibility.
Also I realized the tactic of using red lettering or red's on the covers helps a lot to call attention, since people dont have a lot of time to go through all the entries, they go for the most eye attracting ones. Also having animated gif on your description showing off what you have.