In the Final Rush stage (The track for the Shadow boss) the moon is shown to be intact, during this point in Sonic Adventure 2 where Sonic and Shadow fight on Final Rush, (which is presumably the point of time this version of Final Rush was sucked into white space) the moon was blown in half.
Crisis City shouldn't exist since it was wiped from the time-lines in Sonic The Hedgehog (2006)
Silver and Shadow weren't at Sonic's party but ended up in White Space anyway somehow.
The Pc/Steam port of Sonic Generations is mid titled to "Sonic Generations Collection" due to the Casino Night D.L.C being added in.
Silver lives in the future but is sent back to Sonic's time with everyone else after Time Eater dies and is never shown returning to his time.