Very good game, it seems never ending.
I have to report some glitches in the upgrade system at the end of some level (for example at the end of Archyn planet I choose the 7th level "rocket-launcher" but nothing has changed, still lev 6... and in some planet near Polyaerg-4 I choose the "reinforce" 2nd level instead of the "riffle gun" 2nd level and it gives me the second one instead, the gun.)