On the XBOX360/PlayStation III port of the game (on collections) -- the games are nearly the exact same, so you likely wouldn't meet those missing enemies eitherway. In the Playstation II port (again, on collections), appearantly some things in the game were fixed, likely referring to how some enemies made it back in like previously described on this board.
You could download the Sega Megadrive Collection for Playstation II online, but you'd need a PS2 emulator, and I doubt my iPad can handle that
