Complex sentence: He had no criticisms for the video game "Portal", although by the time "Portal 2" was released approximately 4 years later, he stated that the only flaw of the first Portal game was it's fan base.
Split into simpler sentences: He had no criticisms for the video game "Portal". However, by the time "Portal 2" was released approximately 4 years later, he stated that the only flaw of the first Portal game was it's fan base.