The reason 4 gets so much stick is because after series 3 people can't take it that its entirely different and its been made much easier granted that is true however what you need to remember is series 4 was just the beggining of the build up for series 6.
series 1 2 & 3 are similar concept inside the dungeon and all rooms are in the 3 series at some stage.
Series 1 begins it all series 2 added improvements and series 3 took everything good from 1 and 2 plus its own features to make it th best of the original km trilogy
![Tongue :P](./images/smilies/tongue.gif)
Then the second era begins the pickle era
![Tongue :P](./images/smilies/tongue.gif)
Series 7 technology has really come on along way there and we see alot of scenery for outdoors now is actually computer generated and completly fictional this is kinda of a outdoor series all in its own right and nothing really obstacle wise is in it from the previous 3 seasons has new challenges instead.
Series 8 is a indoor series all in its own right too since nothing from the original 3 is in series 8.
I posted this in the worst series thread but I actually think this could make a good topic all of its own talking about how series 1 2 3 are a trilogy and how they build up for 3 the big pay off.
4 5 6 are a set which build up with 6 being the payoff of that era.
And 7 & 8 are kinda a indivdual series all updated brand new stuff but based upon the concepts of earlier seasons IE series 7 off 4 5 & .6 out door and series 8 with indoor concept of 1 2 & 3.