Addressing questions regarding the game on their forums, Frozenbyte say that Trine 2 will hover between 6-10 hours in length for the average player, but that the focus is on making the game replayable.
Post-release, Frozenbyte will release at least one DLC campaign, which is presently being considered for spring 2012. Additionally, a Linux version of the game will be developed once the PC/MAC versions are complete.
Trine 2 still doesn’t have a release date, but will be out before the end of the year. The Linux version will follow sometime in 2012.