I really appreciate you taking the time to give such detailed feedback—I'll be working on improving these areas going forward. In the current version, leveling up doesn't actually do anything yet, because after some back-and-forth I decided to start by offering only a fixed number of upgrade options after each battle. As for the art, most of it was generated using GPT Image 2, though I did help with interface planning, style references, and quality evaluation along the way.