a. This game's biggest appeal is its combination of various genres.
The kinds of games included in Evoland 2 are approximately as follows.
RPG, Action, Adventure, Platformer, Danmaku(Bullet hell), Fighting, Stealth, Puzzle, Trading Card(TCG), Rhythm, Strategy.
And the advantage of the mobile version is that it is portable and significantly cheaper than the price($19.99) of the pc version.
b. I don't know about it because I'm a plus model, not an iPhone X.
However, according to the article in the previous TouchArcade, it is considered optimized.
"Evoland 2 has controller support on iOS and is optimized for iPhone X from the get go."