Not all missions are necessary to progress in the game, however they are required to achieve full completion.

In April 2003, the centre achieved practical completion.

The continuous formation of products causes the reaction to achieve completion.

The wind farm achieved practical completion on 17 October 2011.

These parts are necessary to achieve 100% completion of the game.

Construction of the facilities achieved completion in May 2008.

Upon achieving 100% completion the play can access Gnasty's Loot.

This first year most apprentices quit and don't ever achieve full completion.

The construction of this pipeline achieved completion in February 2007.