Couldn't gather enough "flexible" mutations because barely any of them came in. I feel the game floods you with different mutations at that point, diluting the pool too much. A slower roll-out of mutations would be better.
Once you get over that hump (heh) though, it's pretty smooth sailing. Harlot is interesting because to get the most out of it you have to use its skill in place of mutation extraction.
The research window could use some work, though. You can only see a handful of possible mutations with no way to scroll or turning the page that I could find.
Wish some mutations would have a physical indicator (thinking especially of Drooly and Long Reach) but I guess that'd be hell to include into every possible sprite. Lust, at the very least, should be visible as wetness on her thighs, though. Maybe let the poor woman climax.