Today I've searched at the 'net after this game but I realized that there's a few totally different games with same name, both Astroblaster and Ad Infinitum so I thought that I should play the game again to be able tell you more exactly about this game.
It's a simple and neat shoot-em-up with simple yet cute graphics. The name is Astroblaster but in game it is called Ad Infinitum.
I've transferred the game to PC and uploaded it to "my" server; you can grab it at http://bubblebobble.c64.org/c64/Astroblaster.t64
The problem with this game is that I can't make it any further than to level 0E (there should be a total of 255 (or FF) levels). When I've reached level 0E the game is telling "Prepare for docking" and everything I can do is move the ship left or right, nothing more. I can't even exit the game or something.
If you know what I should do please tell me. Or is the game faulty? (I guess the latter answer)