"OK, guys, the main story is out of the way, now lets get to work on loading the rest of the game up with 27 metric crap-tons of pure fan service!"
Being able to play the main story from start to finish doesn't mean the game is done. There are several graphics filters, technical issues, voice acting, tuning and many other things to be done. What I meant is that they got the game playable and it is not crashing.