Finished isn't a goal, what are you looking for that we don't have?
I hear there are still a couple features missing like rats and ai (other hospitals).
That is true. Rats, rat bonus levels, AI hospitals, the ability to block off part of the hospital, and newspaper headlines in cut scenes are the significant missing features.
In exchange you get zoom, better heat distribution (buggy in 0.61, use the 0.62 beta), custom campaigns and levels, a map editor, the ability to swap out the music, and support for many more languages.
Feature parity with the original is something we'd like to have. My recommendation if you are hesitant is to play the original first, then if you want the experience to keep on going, try out CorsixTH.