Screwed By The Company: Universe is a big hit in Japan, but aside from the X-Box 360 version, it did not do well internationally. The PC/PS2 version of Universe's Network Mode servers were shut down on March 31, 2010, three and a half years since their launch (October 24, 2006).
The primary reason was Sonic Team's poorly set up management system for the PC/PS2 servers; Sega's American and European branches shared responsibilities (for example, the billing server was in Britain while most GMs and game servers were in America), but all actions taken had to be authorized by Sonic Team. The lack of coordination and screwups that arose from this system caused many PC/PS2 players to either quit or move to the 360 or Japanese servers.
A case example happened during the first year of release, when there was an outbreak of griefing and hacking; this included duplicating rare items and meseta, crashing servers, stealing items from player rooms, and resetting other players' Partner Machines to their initial state (raising a Partner Machine cost a lot of time and money back then). Sega of America's GMs were unable to stop them, thanks to Sonic Team neglecting to give them the abilities to manage the servers effectively. After a while it wasn't an issue, but it did irrecoverable damage and cut the player base in half.
Another major example was the "Error 65" epidemic in 2008, which left many PC/PS2 players unable to participate in the long-awaited "Maximum Attack G" event due to receiving a "Subscription Ended" message when their subscriptions hadn't even expired. Sega of America's GMs announced an extension of the event to compensate players for this, but were ordered instead to end the event early by Sonic Team, who told the GMs to "prepare for a new update schedule." This enraged most of the player base, who blamed Sega of America rather than Sonic Team. Several months passed without updates, until Sonic Team authorized an extension of the event months later. By that point, however, even more players had either quit or moved to other servers.
The second reason for Universe's international flop was the content release system, which gradually unlocked content for online mode every few months or longer, subject to Sonic Team's whims—this often meant delays and long pauses in between updates, while the Japanese servers received regular updates as well as far more frequent special events. When the PC/PS2 servers were still active, they and the X-Box 360 servers shared the same update schedule.
Although most content from Universe and Ambition of the Illuminus was eventually made available for Network Mode, at launch there was very little to do in comparison; only the lowest B-grade equipment was available, clothing choices were limited, there were only a few missions to run, and Moatoob wasn't even accessible. To say that it didn't leave a good first impression on many fans and reviewers would be an understatement.
Misblamed: For the longest time, NA/EU players blamed Sega of America for the lack of content updates when it was Sonic Team who decided when the international servers received updates.