Hey, thanks for the feedback.
Regarding the interface, our original idea had this big interactive area you could walk around, but having a menu makes things a lot easier for replays. The only thing I'd really change is replacing the vertical text buttons with custom icon buttons for each action, but that's just part of making the UI pretty in general.
The heroes' description changing based on your actions is indeed non-functional at this point. One of the bigger challenges is figuring out how to change the heroes based on your choices. The most functional system I can imagine is a limited number of outcomes for each villain, with multiple paths to them. For the heroes, having 4 of them means there's a lot of combinations possible. The story events would have to be dictated by which hero is the party leader. Even with that system, by having every action modify/mutate stats and skills is small ways, every playthrough would be at least somewhat different from the last, without needing hundreds of villain/hero combinations.
The battles are definitely tricky to maintain interest in, which is why I'd consider giving the player control over their villain. If there were more benefits to multiple playthroughs, I think it would justify itself.