So I recently got the Japanese MD version of Ecco the Dolphin and there are quite a few differences between it and the U.S. version.
Thought we should make a list of region differences in different games.
Ecco Japanese Mega Drive
* Sonar sound at the Sega Screen
* All text parts are in Japanese (duh)
* No level intro text
* U.S. NTSC passwords don't work
* Pausing the game pauses the music
* Some of the extra music in the debug option is played in game
* Glyphs act as checkpoints so if you die you have an option to start back there
* The Hardwater stage is much easier
* Vortex's are grey and try to avoid your sonar attacks
* There is a Glyph halfway through The Machine
* If the Vortex Queen eats Ecco you play through the level The Stomach instead of the Machine