Let me cut off the links to Journey to the west that might have made sense first; The cloud and Pigsy. The story didn't need to be based on a journey to the west. Trip could have easily said "I need to journey East" and it could have been the same game. Removing the cloud is easy as it could have elongated the plat forming bit. Maybe even add in a few rope swinging bits. Pigsy is actually the hardest part to cut for this concept as he is the most awesome part about Enslaved. Trip just needs to have a friend of the family that encapsulates porcine behavior and he could easily fit right in.

Now story, plot, and setting don't need a change so this is mostly on the inspiration for Monkey. Both Tarzan and Monkey grow up to defend themselves when their parents are killed early in their childhoods. They have characteristics of apes with swinging and climbing and they learn to speak new languages with the people they meet. 
 

Every time I see Tarzan he has a spear which makes a lot more sense when Monkey stabs robots. The collapsible part is still an innovation of technology. Tarzan meets Jane and he's there to protect her. Trip can still Enslave Monkey since it's actually part of the overall story. Trip is more a Jane than a Tripitaka, for one thing they are both females and second they get stranded with a guy who lives in the "jungle." It even makes girl meets guy more sentimental. To my amusement I would have loved to have seen Monkey do the Tarzan yell instead of "Hey."