Let's address the elephant in the room. Is a Dreamcast CDI collection legal?

The existence of the CDI format is due to a "backdoor" in the Dreamcast's hardware called the (Music Interactive Live CD) format.

The Dreamcast cannot play CD-i discs, and Sega never published games in the CD-i format.

The Dreamcast CDI games and interactive CDs utilize the Dreamcast's capabilities to deliver a mix of video, audio, and interactive elements. The graphics are largely video-based, with FMV games offering a unique look that blends live-action video with minimal interactive elements. The video quality holds up surprisingly well, given the age of the technology.