having to draw out all the animations alone would take awhile. composing music, play testing, and creating the characters voiced dialog would also add on to the time. and with how interactive the environment is, im sure it would take awhile to get it how they want it
As someone well aquatinted with the engine Andyland is using (I've got a demo out for a game using the same engine) I can vouch that a game with this quality of animation would easily take two years to make. It's taken me two months just to make a single level with not nearly as good animation.
