This is the second part of Eartbound (the first one was on the old NES). The final battle is really weird! ... Some kind of acid`s bad trip, especially the end of the battle!
From Wikipedia:
EarthBound, also known as EarthBound: The War Against Giygas! and released as in Japan, is a role-playing video game co-developed by Ape and HAL Laboratory and published by Nintendo for the Super Nintendo Entertainment System video game console. Learn about Earthbound
