The worst thing: If you buy the cart, it won't let you download a patch that prevents the game from freezing in the short story bonus section (DE NNID here).
Region locked bug fixes!!!!
So how are these Art Academy games? Are they actually good at teaching you any skills in art at all?
If you are still interested, I really enjoyed Pokémon Art Academy, which is probably much more basic than the main Art Academy games.
The first few lessons are just drawing faces on shapes and coloring in. It's fun, and you paint "against" a "rival" who will consistently produce the most horrible artworks to make you feel better about your own efforts.
If you stick with it, you can learn some really good lessons about patience, building an image step by step from scratch, lighting, basic techniques... I found it to be quite impressive in its effect honestly, it breaks complicated looking stuff down for you into easy to follow steps, making everything much less daunting and daring you to just stick with it and slowly arrive at great results.
For the price these are going in the bargain bins, I think anyone slightly interested should just give it a go.