The one big and perhaps only enhancement is that the asteroids spin at variable rates as they travel horizontally. Was the "interlaced" rendering applied to facilitate this expanded play? It makes a mess of itself on my emulator, U.K. probably meant for PAL but draws best in NTSC anyway on my system.
Was this created to poke at (pun) the Atari800MacX artifacting bug (see comments original version). Why else would anybody edit this particular game in 2009? Answer is asteroids continue to adorn like decorations even when they rotate on an axis. If you turn artifacting off or disable "new" artifacting mode in favor of old - then those roids turn deadly.