While this game is not as funny or polished as the original DAH!, it has some innovations which make it worthwhile.
Path of the Furon (the 4th or 5th entry in the series) is a fun game, which I believe hasn't been treated fairly by most major reviewers. Yes, the graphics aren't amazing and yes, there are some glitches and frame-rate issues which show up from time to time and prove that the game isn't as polished as it should be, however don't let that turn you off of this game. It is still a solid, if not short action/adventure title.
I won't get into details of the story, more-so the gameplay which is what makes this game so fun. Being Crypto-sporidium (an alien hell bent on destruction) it's essentially about you, destroying all humans. It's a sand-box game where you get such neat weapons as an anal-probe, ion detonator and a blackhole gun (which is very fun to watch suck people and objects into oblivion). One of the coolest things is you learn how to freeze time, and you can pick people up (with your mind) and throw them around and set ion bombs off so that when you re-start the time massive groups of people will be blown up instantly.
Aside from destroying all humans on foot, you can take to the skies in your saucer which has many weapons as well, personal favourites being the death-ray (classic alien weapon), tornado gun (yes you can create and control tornados) and the quantum de-constructor which is nuke-like and can level entire blocks with one shot. The environments are completely destructible and you can level entire cities and watch the buildings crumble while citizens flee in terror.
All in all it's a fun experience, which is somewhat bogged down by technical issues, but at no time did the game become un-playable or lose its sense of fun. Being an alien was only more fun in the original game, and if you liked that one you'll probably enjoy this game as well.