It's a lot of fun, but kinda short and difficult as hell in the later stages. The FMV cut scenes are the cherry on top:
http://www.poetv.com/video.php?vid=60954
"Fun?" with the question mark is a distinct kind of fun. If you are say, not really enjoying the experience on a standard level, but you can't say that you aren't entertained.
A man presumably made of Pepsi runs people down while collecting cans of Pepsi in a race against time to get to a Pepsi machine so he can drink a Pepsi. Also he is ultimately killed by a giant can of Pepsi.