@sleve_mcdichael Found the Problem, apparently, I don't know what the ENTER key is, found the problem on the /dev/shm/runcommand.log file:
fallout2 fallout2 /opt/retropie/ports/fallout2/fallout2.sh xboxdrv: no process found -- [ ERROR ] ------------------------------------------------------ error: invalid argument '--ui-buttonmap a=BTN_LEFT,b=BTN_RIGHT,x=KEY_RETURN,y=K$couldn't convert 'KEY_RETURN' to enum, not a member of EV_KEY Parameters: Executing: /opt/retropie/ports/fallout2/fallout2.sh