Hey,
I've just lost a match because I had to discard 10 cards and didn't notice that prompt was to choose which cards to keep instead of usual discard :/

I know that keeping in end step is visually distinct from normal end step discard, but maybe you should make it even more distinct, e.g. cross out rest of the cards to show that they will be discarded, I'm not sure what's the best solution.

It was time sensitve situation, maybe that's why I missed the prompt, but more eyecatching UI differences would be nice to allow to quickly notice that it's other way around than normally.