Catalypse was a pretty nifty C64 sideways shooter which challenged the likes of Armalyte and Delta towards the end of the C64s lifetime. Sadly Zzap 64 were strangely critical of the game and gave it a low mark, although the game is quite awesome from its intros, the game and the end sequence.
Recently the guys at ready64.org interviewed Andrea Pompili and managed to get an unreleased version of Catalypse which features a number of bug fixes, some including a level 2 loading screen, fixes to the bosses of 1st and 2nd level, etc.
Grab the new version from here:
If also you wish to read the interview with Andrea Pompili, then check it out here: (Note that its all in Italian, and you may need to run it through a translator!)