* It starts off too difficult. Make it get more difficult progressively.
* Maybe have specific progress levels?
* Story: Where is the alien going and why? What if you had differently themed worlds and on each world the alien is collecting some thing unique to it instead of just coins.
* Give some control over the vertical impulse, maybe drop vertical velocity by X units when the player lifts a finger (unless vertical velocity is already less than X)
* Power ups - single hit shield, invincibility (destroys objects on contact), electromagnets that pull in all the coins on the screen, etc
* How about a bonus power up that fills the screen with coins to collect for a short period of time
These sorts of things would add variety and maybe some replay value.
Also the sound when you tap I fins very obnoxious! I turned the sound off immediately.
