I feel like people who didn't watch the original animated series will be confused by
spoilers:end of spoilers
all the space stuff and Prof X being alive. The X-Men were all sad that he was "gone" and the world thought he was dead, so a lot of the general audience assumed he was dead, too. I think they should have shown a flashback to what really caused him to go to space, instead of a single line from Lilandra.