I have a suggestion about the store page: Consider looking into the (somewhat hidden) “Metadata” tab of your project page. There might be important information missing that players might like to know beforehand or even filter for when looking for now games to try.

• Some sense of game progression to give the player more to strive for than just one increasing number would work well to keep players interested longer.
  • Levels, waves, phases etc.
• Enemies of differing size, speed, even movement patterns
  • Gradually increasing each level/wave etc.
  • Makes the player change  the way they play
  • Gives an increasing challenge as time goes by to keep gameplay fresh
• Preset obstacles to force movement strategy
  • different between levels?
• A bigger screen size to account for all this and more
  • less cramped gamespace
  • could return to being cramped later on to provide a challenge
• Something else for the player to interact with
  • Powerups, detonators, etc.
  • Not necessarily another action the player can take, but something else they can do with the one they have ("move")
    • offers the choice of avoiding the creeps or trying to pick up something useful that won't be there for long