It's a great game - I actually played for a while before the video, and decided it deserves a playthrough vid. Great job to y'all!
The pawns intended to be red makes a lot of sense - both in term of consistency with the rest of the enemy pieces, and visibility!
For the keys, I think just an indicator somewhere on the right panel for which keys I've picked up would be enough.
Is the design of the not-trolling room just a visual feature, or it's supposed to block/enable some strategy I didn't think of?
I was wondering about the AI - does it treat me as a simple King, or it knows that I have some tricks up my sleeve?
Also, rewatching my deaths, I actually realized that I wasn't utilizing all of the information provided - namely, the game tells me where visible/nearby opponent pieces move, and specifically told me where that sneaky Knight was, I just didn't read it :)