What is the best way to promote your indie mobile game?

Hi All,

I've created a small puzzle game - Tricky Maze (it's in open beta now - https://play.google.com/store/apps/details?id=com.playrea.tricky.maze)

I'm looking for suggestions on how it can be promoted without big budget. Maybe you had experience in promotion your small indie games. If so, please share your experience.

Feedback about the game is very welcome as well!