Robinson's has a stronger AAA feel:
- A very detailed storyline with 2 side-kicks accompanying you, a robot and a dinosaur.
- Both side-kicks play crucial roles in the adventure/puzzle aspects of the game
- There is a large list of Unlocks that range from personal leisure time (playing basketball, teaching your dinosaur new tricks), to research and filling up your gallery, to finding hidden quests
- There are stories within stories; the story you create as the main character, but also the stories unlocked by the electronic recording devices found throughout the game
To me the biggest difference is that Robinson's is more about "exploration" whereas Xing is more about mental fortitude.
Robinson's leans more towards Tomb Raider style adventure/puzzle, whereas Xing leans heavily towards Myst/Obduction: the player aint exploring a damn thing until their brain solves some challenging mysteries.