Usually contacting people privately because they posted a review in one of your games, is a bad idea. If a person decided to review your project without providing any text, that’s their decision.
I would advice you to let it go. If you are looking for feedback for your project, you can post on Get Feedback, or if you have the budget, hire a testing company.
There is no private messaging on Itch.io, but you can join the Discord Server to be able to chat with others.