I was about to comment, lol
I p much agree with k0bold. Definitely no difficulty scaling to the point that the choices at the end for what stats to increase just don't matter. The gameplay only really exists with the first character, then after they're fully TF'd, there's nothing to do except hold S and sometimes press W.
I don't personally see anything wrong with games that are focused more on the 'fun' than the gameplay, but I'd imagine they'd do better as stories or comics or such instead of games in those instances. Games should have a good mixture of fun gameplay to make the 'fun' more rewarding, imo.
Easy way to fix it, from what I'd see, is have every character's stats separate. So, every character has to start from 0, that way the issue of one character being fully TF'd making the game trivial isn't a thing :)