The Sonic X comic made for a nice tie-in with the show, however, it's ability to last was ALWAYS limited. Sonic X (TV) had a very linear plot, moving from A to Z with adventures in-between. (Sonic & co. getting stuck on Earth, and their main quest to be getting back to their own dimension, via the Emeralds/Chaos Control) If the book was to parrot the show, it would eventually reach the end, and no more could be produced. This comic did not choose that way, it got as far as bringing in the Chaotix, but was composed of ONLY side-stories and could be looked at as a type of "Filler Arc" which used characters from the games and show.
As initialy expected, it's filler style eventually had to end. With Sonic X itself ending quite perilously, and in a way that Archie Comics might not even allow (!!) the book had to be stopped. It lasted 40 issues, and did have a planned ending. Final cover discovered by Streakthefox.