Project Warlock

This may not unlock, I didn't unlock a boss achievement until killing the tank which is fourth boss. It has been reported and I have had confirmation from the devs Crunching Koalas are looking in. Replaying the encounter and beating the boss again may work but havant tested that yet.

Another two stage boss.

First stage he doesn't move so unleash with your weapon of choice, I used tge mini gun which ends thus stage v quickly.

Second stage he finally start to move use the rest of your mini gun and then switch to shotgun or super shotgun. Continuously circle the boss on a wide curve which will enable you to dodge most of his attacks and lead the minions around whilst pumping rounds into him.