This seems like a cool concept, but I'm a little unclear on what's happening. There's a lot of menus that aren't really explained. The main battle screen makes sense and is clear, so that's good. At the same time, because I wasn't sure what to do after the battle was over, it felt a little empty. The good news is that I didn't find any bugs!
However, looking at your notes, this is just a prototype. I think this is a great starting place! A few more heroes and maybe some more clarity on the menu will turn this into a really cool game!