I was under the impression that there was no region restrictions with the DS. Wouldn't 2 roms, 1 from Europe and one from USA be the same size?

I have also come across 2 USA Roms that have been different file sizes. Why would they be different?

 

Ah.. I didn't think of that.

 

3d graphics, sound (the DS uses a lot of (IMA-AD)PCM sound which by nature is massive) and FMV are usually the thing responsible for file sizes of DS roms. Also space was a lot tighter during the SNES era so compression was used more readily (most DS roms merely compress the 3d component) as various techniques like tiles reused with different palettes also were far more commonly used.

For the record though not all gba games are huge: the recent FF titles ported to the GBA are only 64Mbit

 

hah after reading both of your posts, chrono trigger snes + fmv from psx one would probably be an easy feat to port. i doubt it thought since its been done but still...