Overall very cool game!
Rather than the ui being a bit buggy, I think the camera needs a bit of work, maybe some sort of transition between characters, like a fade, or a pan, or a combination of the 2. I also think an option to zoom out a bit, and sensitivity in your options would've been super! Additionally if you were to make the characters a slightly different color from one another, it would make it a little less confusing.
Again, overall really cool! I like the simplistic design :)
I wouldn't mind some feedback on mine if you get the chance :)