In Hardware

I was beated the whole SMB3 game again today, and when I switched game I saw that the SMB3 cartridge didn't show either one of the letters A and B, PAL or NTSC...I live in Norway, so I use PAL, but I got the game from a friend that use NTSC, and I remember that it was it was his only game and he played it all the time. So are there any games that works in both PAL and NTSC?

So far as I know, every game released in both countries will work on both NES's. If you clipped your system, you probably wouldn't notice the difference, as could be the case here. It's also very possible that he had a clipped system before passing it on to you.

Not all games work, there are quite a few games that even when played with a converter, or on your NTSC toploader, will still have graphical glitches.