Captain Planet takes on Animated Superman in an abandoned Metropolis, but both fighters will be in character during this random encounter.
There will be 3 major categories of Animated Superman, since as far as I know, the continuity of some versions of animated Superman is questionable:
Round I) Animated Superman, pre-1987 (this does include the Superfriends timeline as well as the Fleischer canon)- composite.
Round II) DCAU Superman (which does include Justice League vs. The Fatal Five, as confirmed by Bruce Timm himself)
Round III) Non-DCAU Animated Superman, composite (which includes EVERYTHING post-1987 that is NOT considered part of the DC Animated Universe canon, which DOES Include Superman: Brainiac Attacks, despite using the same art/animation style and voice work as Superman: TAS)