I have both a PAL and a USA rom, and I was wondering what version differences are there and which is faster. I know there's a challenge in Battle Arena that has a time limit of 60s in U but 75s in E.

USA is generally faster.

Due to framerate adjustments to compensate for the different equipment, most games of this era are slower on PAL. There are a few exceptions, such as Crash 2 (still NTSC faster for TAS) where a change in the speed of the character overcompensates for the framerate. Feel free to do some testing on your own for this game

I'd imagine for this game, PAL is slower.

i play on PAL, and yeah it's slower. My PB is 25:xx but could be like a 22:xx i think on ntsc