Killzone
The first game from Guerrilla Games in the Killzone series had mixed reactions from press and fans. While the soundtrack for the game was positively received and the sci-fi based setting gave the game some character, there were technical complaints about the frame-rate and the draw distance, while some felt that the gameplay and controls were improvable.
Killzone 2, on the other hand, was found to be a massive improvement when it released in Feb 2009. The game wasn’t plagued with the technical issues of the first one, with the graphics of the game praised. With the game being regarded as one of the best first-person shooters of 2009, you can see that Guerrilla Games took what they learnt from Killzone 1 to make Killzone 2 much better. Future games may not have improved as much, but the improvements and lessons made during Killzone 2’s development meant they didn’t go backwards with the series.