20 mins is ridiculous, speed running to the end if you have a single hold up for 1 min or so the run is dead. Get rid of the 2 phase on the boss or give us 5 more minutes. Even 2 more minutes. The boss and in fact entire mission isn't hard it's the fact that you have to speed run the whole mission just to have enough time to get thru the 2 phases. Do the developers even play this game on legend? And add in the fact that to upgrade the gun we have to do this every week until final shape is just repetitive and annoying. Timegating needs to go. Pure laziness. .