Dead Effect 2

Simple enough on easy.

The boss is essentially just a slightly larger version of the other drones already encountered in the game, with the health and damage you'd expect from the games bosses, no new abilities to worry about.

You are going to want either;
A high damage, semi-auto weapon (Shotgun, Grenade launcher) and Giga Shot (Next shot gets huge damage boost, 22 sec cooldown fully upgraded)
OR
An automatic weapon (assault rifle, plasma gun ect) and the aptly named Damage boost (almost 7 sec @ 315% dam, 25 sec cooldown fully upgraded)

;Depending entirely on your playstyle.
The "Countdown" doesn't begin until so, even "losing" 5 sec there, on easy with a great weapon/ability, you should'nt have any trouble finishing him under 30 sec.

My last advice is that melee is out as he likes to fly away after a few hits, pistols CAN work if you buff them, and use Bullet Time BEFORE your other ability of choice if you are worried about aim.

Happy hunting (>*_*)>