Thank you very much jarnMod!
Yes, Creepy Mahjong is definitely a niche game, definitely changing the theme to sexy anime girls would increase the sales of a similar game.
I might try the same test again for a future game, that is different and see what's happening. Of course there isn't a fixed rule for this, since there are so many variables involved that makes a lot of difference, but yes, the type of game, its niche, the request for a new game of that type and the offer, heavily influence the result.
Thank you for checking the video and sharing it! :-)