For 5 dollars I wasn't sure what to expect, so far the AI is easy af. However the game also doesn't tell you when you have tenpai at all, so you actually have to pay attention to your hand and your opponents discards unlike in games like Mahjong Soul. (I mean yes, you pay attention to your hand in those too, but not at the same level as "real" mahjong). I've had multiple draw games against the AI but so far it hasn't scored a direct hit and I'm in first place with over 41k points.
Edit: There is one time the game will tell you you're in tenpai and that's when you have a closed hand and can call Riichi. It won't tell you what your waits are though. Also there's no option to turn on Numbers so you have to actually learn the tiles.