The prototype version of the game contains several (very buggy) removed levels, but also some other changes. Most notably, Ripper Roo was originally located at the end of the first island, along with "Up The Creek". (This would explain his rather awkward placing in the final game, just two levels into the second island.) The fight is also somewhat harder, and his laugh is slightly lower-pitched. There were also "POW!" crates, which don't kill you (oddly enough), but make a pretty explosion when broken. A precursor to Nitro Crates, perhaps?
Tiny Tiger and the Komodo Brothers were also designed to put into this game (hence their cameo in the prototype intro above), however they were omitted and spared for Crash Bandicoot 2: Cortex Strikes Back.
Uka Uka was a sprite in very early stages of development and Crash collected actual fruit instead of the fictional Wumpa fruit.