The post read simply:
Support for high resolutions, ultrawide monitors, and high frame rates.
Sonic Unleashed DS ROM Fixed Exclusive: The Ultimate Guide to the Fan-Made Port
If you are a Sonic completionist, you owe it to yourself to play the DS version. The daytime stages are arguably superior to the Wii/PS2 versions. And if you want to play them without the headache of random freezes, missing audio, or save wipes, the "Fixed Exclusive" is the only way to fly.
The community has attempted to fill this gap with several projects, though none have reached a "fixed" final release: STICK O'MEDIA Port:
