You pointed out that Dynasty Warriors keeps the same levels every time. But that is not strictly true. Many DW fans buy the next game as the level design has changed. Like for example level A might have a river with one bridge and two castles in DW 3 but then in DW 4 it has not bridges and a seriers of small forts.

Many people did not like DW 6 as it changed too much of the combat system. Koei were trying to please the critics that said the games stay too similiar but then the critics still gave the game terrible rating. Its not fair on omega force. I mean look at the metacritic ratings for Dynasty Warriors 2 and 3, the critics loved them, the fans loved them. To keep their base omega force did little to change the core game through DW 4 and 5 which brought them critical hatred but retained their fans.

Now with DW 6 they are loosing alot of fans because of the new system and cloned movesets. They changed too much in the fans opinion but in the critics opinion they did not change enough of the game.

How do you keep both happy? It's beggining to look impossible, in madden fans expect a football game and critics expect all the extras but in DW fans want all the extras to stay the same and the combat to stay the same however critics want it all to change. Ha thats just my opinion :P