It makes complete sense that it is in the same universe, it just comes gradually.

Instead of hopping around time, you are in one similar place in time, hopping between a real dimension in where serge died 10 years ago and one in which nothing at all has happened. It causes major rifts and you manage to recruit people from both dimensions, it is really cool how it plays out and how different things play out just because in one dimension the protagonist is believed to be dead.

It isn't supposed to play just like chrono trigger, in gameplay or story, but it does envelope itself in the same overall universe quite well. Damn I love both of these games so much.

I'm glad you said you'll give it a chance the pacing really gets awesome once your party starts going after lynx.