thx, i already got 7zip since a longer time. BiggAdd's tip solved the prob, thx dude!
edit: wow, thats a lot of fun! a very stable foundation, but there could be a lot more to keep the fun high!
look at this as an advice:
What about moving targets? like spaceships or meteorites that attack the players ball thing? and a explosion efect for the planets.
and at last scroll the texture of your background, it adds a lot more depth to the game optics. make a second layer with only stars and move it even faster, like the backgrounds in old 2d plattformers, if you get what i mean. parallax scrolling or what ever they're called.
and make different planets, it adds some diversity, what is always a good thing. maybe smaller ones which may give more points. and stuff like extras...