the real issue with the xbox is the video card it used , it had a custom nvidia card , that was between generations , it had all of the features of the generation of cards that existed then , and 2/3 features from the next generation , but not all of the features from the next generation
also while xbox games run on x86 , they dont use exe files , ive looked in them and they dont have exe's they have xbe files , plus it's directX version from what i remember was also a mix of versions like with the nvidia card