Well last night I dug up my Atari 2600 and had a crack at that. Didn't seem too hard as it was a fairly slow pace band the graphics were rough as guts. Good for a bit of quick fun but I couldn't really see myself getting into it too much. I managed to get a score of 33,750 after about half an hour of playing.
Then tonight I thought I would give the arcade version (red label) a go on MAME (PC using keyboard) and boy oh boy, it is a completely different game! The graphics are much better, I can actually see what is going on! But the most notable difference is the speed the arcade version is much faster but there is also a lot more enemy types. I now understand why everyone is saying it is so hard. After playing for about 45 minutes my best score is 16,475 wich was a bit of a lucky run as my next lowest score is about 7,000.
