Just because you guys were talking about this game I pulled my SGX out off the closet and plugged it in. I've tried 1941 and GnG. Hey man, GnG is REALLY hard. After dying several times while trying to climb the hill in the 1st level, I got a little bit frustrated. But I tried and tried and after 30 minutes I made it to level 2. Wooooah!
Then I tried to remember if I ever have seen the boss of the 2nd level. I think not. But it's a lovely nice game.
1941 disappointed me a bit. I thought it was a bit better, graphicwise. But still a solid game.
The instruction manual is indicating that the other 3 levels exist ;-)