[adenozine]

I thought this too at first, but this is where the real strategy comes out, because you can guess MULCH and that will tell you if it's LATCH or MATCH. or CLIMB, that would also eliminate BATCH. There's intelligent ways to guess to eliminate more letters. Hard mode is only hard because it eliminates this possibility of constraint narrowing.

I think Hard Mode is not a good name for it. The game is already plenty hard.

[frosted-flakes]

I think Strict Mode is a better name.