12935 -> TIZZY (5625) -> OXBOW (2674) -> GRUFF (858) -> MAMMA (195) and I'll let you guess the rest but my next choice left 43 words, and I survived with only 4 words possible.

The rules not letting use a letter you know isn't in the target word drastically cuts your choices, your best bet is to use as few unique letters per word as you can, and as uncommon letters as you can, but as all normal words need vowels you'll be forced into only picking a vowel from the target word soon enough. Try to find letters that are in the word as late as possible so you're not locked into having to use them.

Once you are forced to use letters from the target word, avoid placing them in the right place. Sadly there's a rule not letting you use a known letter more than once in a word (once A is known, you can't write ALPHA), and a rule for not letting you put a known letter in a place you know it doesn't go (so after MAMMA, you can't have HALVE because you know there's not an A in second place, nor ALPHA because you know there's not an A in fifth place).

> Sadly there's a rule not letting you use a known letter more than once in a word (once A is known, you can't write ALPHA)

This is not entirely correct (or at least it's worded a bit weirdly).

If you know that A goes in a certain place you can still try a word using A more than once. It's only once you know that A does not appear twice (because you tried a word containing A twice, and the second A way gray!) then you can no longer use A twice.

In your case you tried MAMMA which contained 2 As and the second one gave you the information that there's no second A.

The best I could do with today's word, and the wordlist, but no scoring function to minmax the rules:

- FUFFY (8159) (shipping of Faith and Buffy from Buffy the Vampire Slayer)

- IMMIX (4544) (to mix or blend)

- ZOCCO (2142) (low plinth, from the Italian word for sock)

- QAJAQ (530) (alternative form of kayak)

- TRATT (155) (clipping of trattoria)

- KHAPH (7) (alternative form of khaf, the 11th letter of the Hebrew alphabet)

I get the feeling that if this game had 7 steps instead of 6, it would almost always be impossible.

> Sadly there's a rule not letting you use a known letter more than once in a word (once A is known, you can't write ALPHA),

That rule doesn't make sense.

What if the answer is AORTA, and you want to guess ALBUM and then ALPHA?