One thing I'm trying with my download games is to put a credits page at the end with a link back to the games project page. Might make it easier for folks who downloaded the game to come back and leave feedback.
I too am somewhat disappointed by the level of feedback and discussion about games on itch.io. My most popular games has almost 1,000 downloads, out of which it's got 4 ratings, and two comments - and one comment was asking for an android version. I do seem to have quite a few followers, so maybe that's a better guide to how well you're doing.