About the download:
Its kinda much work, only to see some outdated version, not much people will go trough that.
Try to compile an standalone jar (maybe with some extra files) so users can check your game withing a click.
The graphics:
The levels (background) seem nice, only the player / obstackles are kinda boring, try to create some better materials.
Even a few pixels here an there can make the terrain much more attractive.
Gameplay:
I dont know what limitations android has, but try to all some extra gameplay into your levels, 30 levels of jumping over spikes can get boring.
Some suggestions:
- Moving obstacles
- Moving screen (like mario), cant see if you already implemented this with the screenshots.
- Diffrent obstacles
- Power ups / handicaps
Other:
It could be nice if you included the level editor, so people can challenge eachother with their own levels, but i guess you already planned this.
So far my comments, the game looks good, nice and simple

Keep it up, i would like to see the endresult.