@vetsin, either you lack OGG support, or the game can't write into its directory. If permissions are the problem (and they shouldn't be if you installed the DEB), you'll need to chown the game directory, so it can write into it. Sound requires some temporary files written there. Also, your setting probably aren't being saved this way. Or, more probably, you lack OGG decoder, so install ogg-support with sudo apt-get install ogg-support libvorbisidec1

@Wreck, I actually added a damage bonus to the manual mode, to encourage its use. Seems the laser tower is a major problem now, I'll probably remove the burst fire mode and maybe lower the damage a bit alltogether. New damage types and resistances aren't likely to happen, too complex to do these things now. (I'd be happy to make a sequel some day, though) But, as mentioned earlier, some more balancing and a "hard mode" might do the trick for this current major iteration of the game. Also, thanks for the comment and rate at Google Play