Compared to the drab humorless other entries, Beam stands head and shoulders above the others for their effort in trying to inject a bit of levity into the genre. War may be Hell, but it is also prety damn funny sometimes. While the Series 9 and Survivor units look like they could have been ported from RA or TA, the Evolved are rather ingenious. Instead of solar collectors, you get a big pig. Instead of an oil tanker, you get a bull ant tank.
Tanks are massive crabs or beetles.
KKND2 also makes good use of line of sight and terrain height advantages. Units can't see beyond trees that block their view. That means they can also hide in them. Units on cliffs can fire on units down below, but only artillery units can shoot up at them. The waypopint system has been improved upon and is better than in KKND , and brings the game more in line with the others in the genre.