Know-How Exchange : Advertising/PR

As well as Android, develop an iPhone version. Lead with the news that you're giving the game away for free.

Do this in every kind of game-related forum and in every kind of game related social platform you can think of. For the search term ""android game forum", there are 17,800 pages of results on Google alone.

If its appeal is strong enough, if the game is challenging, if its levels and difficulties trigger some kind of social appeal and an element of bragging rights, word of mouth will drive demand.

This first phase needs to be given away. By doing this, you'll create a community—a user base—to whom you'll then offer game version 2.0.

This next version will be a paid version, with a low barrier to entry of no more than $4.99. By creating your community of users, and by then giving them more challenges in version 2.0, you're likely to generate sales.

Good luck.

To add to Gary's reply:

Think deeper about the game's target audience. Do they have particular interests? For example, if the game appeals to math-minded folks, try seeking out related forums and social media outlets. If it deals in trivia, perhaps a group of Jeopardy enthusiasts might be a great place to start.

Do you have a budget? If so, there are some incredible Facebook and Instagram advertising options where you can target your very audience in an engaging way.

Is the game very visually appealing? If so, an Instagram photo or short video may be an awesome way to reach your audience.

As for specific promotion content, that's really hard to say without a full brief, but remember to be concise, and perhaps a little mysterious.