Setup a Twitter account and post tweets with hashtags that get lots of re-tweets (like screenshotsaturday, indiedev, gamedev etc.).
Create a Linkedin profile for yourself and join gamedev groups to talk about your development(s).
Use Facebook?
Link your twitter, linkedin, Facebook and websites together so updates will propogate to the other sites where possible.
Make a Youtube Channel, and some videos of your game, or videos of people playing your game, or of people responding to people playing your game etc.
Post about your game in related forums (don't just spam forums or risk community wrath!).
Go for Steam Greenlight - whether you get it or not, it is still more exposure for your game?
Do a Kickstarter (same reason as above)?
Tell all your friends and family to download and leave nice reviews.
Tell all your friends and family to tell all their friends and family to download and leave nice reviews.
Tell all your friends and family to tell their fr.... you get the idea.
Reviews come over time. Encourage reviews by responding to critic left by users (i.e. "User: I can't close the video add"... "You: fixed for next update" etc.) or by offering a reward for likes (check ts & cs)?
There is a nice marketing thread
here.
