c compiler adapted to the limited ressources of epiphany would be great (although it probably requires the 64-core kind to get more local ram). but unfortunately c-compilers are usually the kind of task that would occupy several people for a lifetime or more. you can't do anything else then since you'll constantly have to work with bug-reports from a very wide community.
3d stuff and physics engine requires a lot of mathematical knowledge, so if your education only covers it then you'll soon get into a dead end with your knowledge about parallellization.
for a really powerful computer you actually don't need loads of ram, and with only 32 bit you can't have more than 4 times what parallela already has anyway -- minus the ram for gpu or whatever. I think more interesting would be to turn parallella into a wearable computer, maybe combine it with google glasses or something. another interesting thing would be to port to the parallela platform (i.e. create an arm backend and make epiphany available too), since you know c++ it would be interesting to show pople that even on the limited amount of space you still can make programs in a higher level language...
but if you insist on using epiphany in a desktop pc, maybe turn parallella into an usb-stick? would definitely be easier than attaching epiphany chip on another motherboard or adding more ram. and there are enough tiny-sized 64bit pc to make the combination of the two extremely powerful -- just watch out what memory-restrictions they have...
btw, what I said here is a reply to c1d, not my own ambitions. I'm just making suggestions for someone with this particular set of interests.