Complex sentence: On June 30,2006, "TrackMania United" was announced, a version that amalgamated all previous "TrackMania" editions into a single game that includes all the environments from the earlier games, and subsequently future installments of the series.
Split into simpler sentences: On June 30,2006, "TrackMania United" was announced. The game is basically all "TrackMania" games built into one game that includes all the environments from the earlier games, and, later, future installments of the series.