Though we'd be straining to tell you specifically what has changed with v2.23 since Google evidently doesn't believe in change logs or auto-updates via software (rolls eyes), we can tell you that this is a newer version from v2.09. Yep. That's why we get paid the big bucks here at WMExperts.
Actually, some of the controls during play seemed to have changed a bit (shrunk down?) and there seem to be some nice animation effects. But perhaps that's just out imagination. Maybe you can help discern the mystery.
Anyways, go here to directly download the .cab to your phone.