If you look at the images on the link above, you'll see there is box art for two distinct versions. One is the original first release in a red box with no rating. Later on, after the creation of the ESRB (largely created due to this game specifically), a new version was released with the updated Sega CD blue spine and an M rating.
Currently, there are separate listings for the 2021 reissues done by Limited Run, but the original two versions from the 1990s are listed as just one release.
At this link, you'll see images for two different versions. One is the original retail release that came in a black box, with a black disc. The second version came only as a pack-in with the Model 2 Sega CD system. This version does not have a retail box. It only includes a blue disc with "Not For Resale" printed on it, housed in a generic CD jewel case with no inserts, and a smaller manual with a blue spine:
Night Trap - Sega CD
https://www.pricecharting.com/game/sega-cd/night-trap
If you look at the images on the link above, you'll see there is box art for two distinct versions. One is the original first release in a red box with no rating. Later on, after the creation of the ESRB (largely created due to this game specifically), a new version was released with the updated Sega CD blue spine and an M rating.
Currently, there are separate listings for the 2021 reissues done by Limited Run, but the original two versions from the 1990s are listed as just one release.
Sewer Shark - Sega CD
https://www.pricecharting.com/game/sega-cd/sewer-shark
At this link, you'll see images for two different versions. One is the original retail release that came in a black box, with a black disc. The second version came only as a pack-in with the Model 2 Sega CD system. This version does not have a retail box. It only includes a blue disc with "Not For Resale" printed on it, housed in a generic CD jewel case with no inserts, and a smaller manual with a blue spine: