Definitely valid critique! And I appreciate the kind words.
I do agree that it's hard to see which one you are playing as, so we added a little white aura around the currently active one. It's hard to see though, so I wouldn't blame you for not noticing. And for the "undo" option, that's simply because we didn't have enough time to make levels where the mechanics had to be introduced to you one at a time, rather, to pad out time and give the players challenge, we had to just dump a bunch of high difficulty levels towards the end. Not ideal, but for three days progress, I'm still happy with it!