I dunno, it seems like it's based a lot on luck. I was doing perfectly fine until like 4 queen bees ran into my web at the same time. Not only could I not eat them fast enough to prevent swarms of bees, but by the time I got through two of them I was practically dead.
@Evilbottom: Actually, many of the missions in the game were first taken from Hitman or Hitman 2. Just before you go off on saying they were stolen from GTA4.
On the last mission, I think that people are saying "you can't shoot and the mission breaks" is because you don't shoot the people. You have to look for environmental stuff to shoot at, but shooting the enemies won't register.
It's ok...except I ended up buying everything really fast. If you don't buy any of the extra guns, you can buy the final one on like the fourth level. Just don't miss any shots and you'll be fine.
It's ok, nothing too special.