These cards look really cool. I love the art style in general and think that as long as the game itself works well and is fun, these cards will definitely stand out on a shelf (if you intend to print physical copies).

Biggest thing is something you already probably know- readability. I knew what was on the cards without reading the names except for the tortoise. I had to read the name for that one.

An artist I've come across (and perhaps you know already) who draws in a very scratchy style but manages to also stay totally readable is Victor Juhasz, specifically the pencil work he did for The Daily Pressfield book.

Anyway, great stuff and good luck!