An often missed point from many app store optimization topics is "great first impression".
First impression matters tremendously for any app, and more so for mobile games.
A first impression will hook a player longer. So make your first impression BIG!
Take a look at the intro of the first Half Life game. Or Elder's Scroll: Morrowind when you first step off the ship.
The impressions from these games are still fresh in my mind many years later. (OK. The Half Life one got annoying the 3rd time around).
When making your game levels, start off the game with one of your best aspects and effects shown.
Its often a habit to keep our best till further into the game, where we think that a gradual improvement will keep users wanting more.
While this may be true in some cases, it can also cause your users to forget about your game after the initial game play.
Big impressive impressions, when it comes to mobile games, should also take place at the stores.
You want a potential user to be impressed when they first see your app's page.
Ensure your first 2 or 3 images are the ones with the biggest bang.
If you have a video, make that impressive (explosive!).
Avoid showing the title screen or the game menu as your first screenshot. I often see indies making these mistakes. It kills potential conversion.
So, go get this part of your ASO fixed and improve your downloads.