Wow, you got a donation? That's really generous of the rater. Congrats, man! But as far as getting more ratings, yeah basically just go out and play other people's games, rate and leave a comment on what you liked, suggestions, etc. People will usually return the favor but on top of that there is a "karma" feature that itch.io has where the more you rate and comment the higher your game shows up in that organization selection. It shows people who click on it who's actually active in the community and would probably actually read and respond to any feedback you give to them.
Edit: All that said, I'll be sure to try your game and provide a rating & comment later today :)