I should just not mention the educational stuff in the advertisement
What is your target audience? People wanting to learn. People wanting to play an action adventure.
If your audience is people wanting to play games, it might not help to highlight the educational aspects. Oh, there are games like that. For language learning. Or history learning. And all sorts of topics. And the developers might sugarcoat the learning material with a game, so it does not get boring.
Would you play a game, if you see the educational tag? Or would you assume it is one of those games that disguise lectures as a game? Add to that some rather boring screenshots where different places are shown, just like you would see in history class, and my first impression would be clear - and possibly wrong.
It depends what your game really is. Was some gameplay created around the topic, or was the topic used as fluff for some rpg game? Since you used the phrase "inspired" and not "based on" in your description, I would assume your game is historically as acurate as all those ninja games with black robed fighers are about Japan. And people do not play games with ninjas, because they want to learn about historical spys, but because ninjas are cool and a good excuse to have a fighting game.
Your game seems to have a witch from folklore as an excuse to have a magic rpg game.
Yes, you can use animated screenshots. Just look at the games in https://itch.io/games/tag-action-rpg/tag-rpgmaker . As a random example, just hover your mouse over the game Echo-Our Voice. Even in the hover screenshots there are animations. And those animations make abundantly clear, that this is not a rpg maker turn based combat style type rpg game.
Look at other examples and think about, if the advertisements those games do, would apply to your game. I am talking about the features those games do highlight with their screenshots and description.
And if your game is such an action adventure, you should also look at the tags those games use. People looking for that kind of game will look there.
I thought that Itch being much bigger would get it more attention
Itch has 1.3 million games and not really a big audience. The most popular developers have maybe 30k followers. And even a "known" developer like Hempuli has only 12k followers. But the game Baba Is You has 20k reviews on Steam. I knew Baba years before I even knew Itch existed.
There is little promotion done by Itch. Compared to Steam, they do zero. On Itch you might visit the recommendation page, but mostly you will browse tags for your interests or visit the popular pages, or both.
But even for the recommendation pages, you will need accurate tags. You have 1 main genre and 10 freely choseable tags/genres. You should chose tags that people will use to find games like your game. And tags that describe the game and make it appealing to the target audience.
https://itch.io/games/tag-educational is actually in the genre list on the left side. Look at games in there and decide, if it fits there or not. Same for the other tags.
The first step is having people see your game in their browsing lists. For which tags are good.
The second step would be to make it appealing to them by showing in the screenshots and desription, that it is indeed a game they would like to play.
And the third step would be to make good on the advertisement promise to get good ratings, instead of disappointment ratings.
That's my opinion about how all this works.