@Gama11 Thanks. The difficulty does increase as the levels go on, but I am working on various other things (music, sound effects, upgrades, new enemies, etc.) for the second version. I could not just upload a new version to the same gamepage because the current high scores would be messed up.
@10tacle thanks. not talented enough to make music... And I used to have 15 lives, so be glad I didn't publish that ;-) For the panic button, you can use the menu button, it SHOULD submit your score.