Hmm, I've never tested PS2 controllers. But if you say it's working with the rest of the Android OS, then we should be able to support it in game as well.
Can you try installing the latest alpha release of the app? A lot has changed since the version that is on the app store. Please go to this thread and install the latest APK from the first post. Don't worry, you can install both the published version and the alpha version side-by-side on the same device.
http://www.paulscode.com/forum/index.php?topic=1818If you still can't get the controller to work on the latest alpha, then go do the following
- keep the controller plugged in
- go to the main nav drawer in the alpha
- tap About -> Hardware info
- post back the information that is displayed (use the share button to cut/paste).
In the alpha, you can also test the controller using Help -> Controller diagnostics from the main nav drawer.