Yeah this went kinda horrible. I think probably the easiest way to do this boss is to have lasergun ammo available so you can shoot his rockets out of the air a lot more easilly and deal more damage as well. I can't imagine him being very hard if you do that. Though I suppose it's also possibly easier if you don't hide in the middle the entire time. I dunno.
Boom boom!
Blind playthrough of Serious Sam 3 with commentary for the funsies! Played on Serious difficulty.
Playlist with the rest of the playthrough:
http://www.youtube.com/playlist?list=PLBCBDD46FBEE61917