Hey folks, figured I'd write a quick article on getting online in Sonic Robo Blast 2. Unfortunately, there is an issue with SRB2 v2.0 where the Master Server address - where you get the list of online games - is actually wrong in the default config file. If you're having trouble fetching a list of games in the server list, this is likely the reason why.
To fix the problem, simply open up config.cfg in the SRB2 folder with any text editor (Notepad is fine) and search for the variable "masterserver" - change "srb2.servegame.org:28900" to "ms.srb2.org:28900" and you should be able to see all online games when browsing the server list (your games should also correctly register on the MS). This shouldn't be an issue in the upcoming 2.0.5 release, as the default masterserver address will be the correct one.
Also, if you plan on hosting a public game on the Master Server, please read the Master Server rules first, thanks!
Hope this solves any issues with trying to play Sonic Robo Blast 2 online. Have fun!
Edit: Also, please note that the 2.0.4 patch is required for online play. Download that here: Moddb.com