Complex sentence: Techland also did not agree with the creative vision of "Dead Island" and considered themselves "not in a very good business position" with "Dead Island" and decided to split with publisher Deep Silver and start developing "Dying Light".
Split into simpler sentences: Techland also did not agree with the creative vision of "Dead Island" and considered themselves "not in a very good business position" with "Dead Island". Therefore, Techland decided to split with publisher Deep Silver and start developing "Dying Light".