I didn't think Prehistoric Man for the SNES was terrible, but then again who cares what I think? I'm Splash/Not Available.
Gundam Side Story 0079 is actually translated pretty accurately. You know the NES game "Ninja Gaiden"? I peeked at Wikipedia and this Dreamcast game is called "Gandamu Gaiden" in Japanese. It's the same "Gaiden" (外伝 ), meaning "spinoff" or "side story".
I guess the word "Gaiden" just sounds cooler to us Americans than "side story" does, lol.