Amiga A 1200, games not displaying properly (composite connection).

[Bother]

Hello,
  I've tried searching for an answer but couldn't find one.

 I have an Amiga A 1200 HD (NTSC) that I bought for Deluxe Paint.  Everything runs fine, (the Workbench and Deluxe Paint 3+4), until I try running the games included with the Amiga Magic bundle.  Pinball Mania's screen is too low, so the bottom is cut off.   The game 'Whizz' Shows a software company screen and beginning animation cartoon just fine, but when I get to the title screen and while the game plays, the screen constantly rolls downward.  Those are the only games I've tried/have.

 I've tried connecting the Amiga through a composite cable to a Sony Bravia LCD and a large CRT television with the same results.  I don't have a monitor to try the RF cable.

 Do I need to buy something else to make it run properly?  I'm just trying to find out if the computer is damaged.

Thank you.

[Bother]

Thank you guys very much for helping.  I'm hoping the answer is that  I'm trying to run PAL games.  If PAL doesn't work I'll just try buying a  couple of games here.  Again, Deluxe Paint 3 and 4 display correctly  and the Amiga is set for NTSC (just checked).

It seems none of my tv's have an RF input.

Question:
   I'm ready to try setting it to PAL first, but if it's an incorrect  setting, will I still get an image on screen to change it back to NTSC?   Or would there be another way to set it back?

[Bother]

Thank you.  I gave it a try.

Screen constantly rolls down right when I make the switch at the PAL/NTSC select screen.  Pinball Mania scrolls.  Whizz behaves as it does with NTSC.

Does this help reveal the problem?
I'm going to buy Marble Madness or something and see if that works.