Excellent follow up to the first game, a seriously "Mental" game, even in 'Hippy' mode - This game has just about everything and well worth the high review points. The sheer size of the playing areas take some time getting used to, the puzzles are are cool though I still cannot find 100% no matter how hard I try. The volume of enemies really is outrageous. Some of the levels are a tad difficult and some of the 'Secrets' I am sure are not where they are supposed to be - spent 3 hours on one level to find them all and still manage to find one short of all of them. I try to avoid cheats and walkthroughs and much prefer to work at solving games without them. Well worth the effort though - have played this game about 9 times and even my better half has played it albeit in hippy mode, great fun - respect to the programmers - bring on Serious Sam 3, hopefully.