While Opera is a fork of 4DO/FreeDO and therefore largely compatible (or incompatible) with the same software they are… more and more changes are being made which will start impacting that overlap. While tickets should be filed for any bugs and incompatibilities found this list will help others looking to see if there are known issues with a title.
|Super Street Fighter 2 Turbo (US)||The speed indicator is offset to the left by 12 pixels. github ticket #73
The intro sound offset is not a Opera bug. It is in the retail game.