I personally wouldn't play this slot because I'm not a "Madoka Magica" fan, even if its RTP was 99% instead of 96%-98% in slots I normally play. But if I were a big fan of these anime television series, I would play it even if its RTP was 94%.
Generally, your factor and consideration of playing slots depends highly on
"Themes>RTP".
If that is so, you might miss some of the good slots with better RTPs since themes are a factor for you. Well, regardless and we already know about this fact,
even how good the RTP is, it doesn't mean we will have a good luck on that slots so nothing wrong with your criterias of choosing.Sometimes, players really prefer to choose a slot based on themes over anything else.Exactly. And they are not losing much, money-wise, as you rightly pointed out. And by "not losing much" I mean they are actually not losing anything, unless they are making a million spins per day. And surely they aren't, because there are only 86,400 seconds in on day, and you physically can't make more spins than that number. So, the difference in RTP is not affecting them.
~ I think that slots with Japanese characters or manga will not be famous outside of Japan because these characters are familiar to a very narrow circle of people. In my opinion, to increase interest in slots, you should use more well-known characters or use a neutral theme that suits anyone regardless of where they live, interests, age, etc.
Firstly, Japanese characters are very famous outside of Japan. Secondly, the current population of Japan is 125.8 million. Basically, you could target that audience only and it would be enough.