Beta 2 vs. Final

There are quite a few things different from Beta 2 and the final ROM; a lot of them being minor differences. Here's a list of the main differences:

• When the game is paused, you can move around in Debug mode
• A lot of the sounds are different, for example:
  • There is no "SEGA" sound
  • In-game music is slightly different
  • Sounds here and there in the game are different or not there at all
• The options menu is inaccessible, and there is no music or sound at the title screen
• All levels (except The Machine) are accessible from the title screen
• Different animals come out of robots when you destroy them
• There are no rings in Showdown, and the final boss can't be defeated
• There are no "demos"
• The bonus stage you enter when all rings are collected is different (there is only one), and there are no other bonus stages

A complete list of differences between Beta 2 and the final ROM can be found here.