Sorry for the slow reply, and thank you for playing this long. 280 is a serious score.
You've put your finger on the real problem with the late game. Platinum is currently the top of the ladder, so past it the game stops giving you anything new, and worse, the board only ever shrinks. Once enough of the floor is gone you're not making decisions anymore, you're just repeating the one move that doesn't kill you. That's the opposite of what this game is supposed to be, since the whole point is that every turn should be a real choice.
So that's a fix, not a maybe. I'm looking at giving the board a way to recover so it stops decaying into a single safe corner, and at adding something to chase above Platinum for people who get that far. Thanks for pushing it far enough to find the ceiling, that's genuinely useful.